diff --git a/data/json/overmap/multitile_city_buildings.json b/data/json/overmap/multitile_city_buildings.json
index c7dc0a5cabe68..ed7fde304273c 100644
--- a/data/json/overmap/multitile_city_buildings.json
+++ b/data/json/overmap/multitile_city_buildings.json
@@ -1724,7 +1724,8 @@
       { "point": [ 0, -3, 2 ], "overmap": "police_dept_d012_south" },
       { "point": [ 1, -3, 2 ], "overmap": "police_dept_d112_south" }
     ],
-    "city_sizes": [ 14, -1 ]
+    "city_sizes": [ 14, -1 ],
+    "flags": [ "CITY_UNIQUE" ]
   },
   {
     "type": "city_building",
@@ -2259,7 +2260,8 @@
       { "point": [ 2, 2, 2 ], "overmap": "megastore_1_2_roof_south" },
       { "point": [ 1, 2, 2 ], "overmap": "megastore_2_2_roof_south" }
     ],
-    "city_sizes": [ 12, -1 ]
+    "city_sizes": [ 12, -1 ],
+    "flags": [ "CITY_UNIQUE" ]
   },
   {
     "type": "city_building",
@@ -2285,7 +2287,8 @@
       { "point": [ 1, 2, 1 ], "overmap": "hospital_8_roof_north" },
       { "point": [ 2, 2, 1 ], "overmap": "hospital_7_roof_north" }
     ],
-    "city_sizes": [ 12, -1 ]
+    "city_sizes": [ 12, -1 ],
+    "flags": [ "CITY_UNIQUE" ]
   },
   {
     "id": "urban_35_hospital",
@@ -2327,7 +2330,9 @@
       { "point": [ 1, 0, 6 ], "overmap": "urban_35_31_south" },
       { "point": [ 0, 0, 6 ], "overmap": "urban_35_32_south" },
       { "point": [ 1, 0, 7 ], "overmap": "urban_35_33_south" }
-    ]
+    ],
+    "city_sizes": [ 8, -1 ],
+    "flags": [ "CITY_UNIQUE" ]
   },
   {
     "type": "city_building",
@@ -2977,7 +2982,8 @@
       { "point": [ 0, 1, -1 ], "overmap": "cathedral_b_SW_north" },
       { "point": [ 1, 1, -1 ], "overmap": "cathedral_b_SE_north" }
     ],
-    "city_sizes": [ 14, -1 ]
+    "city_sizes": [ 14, -1 ],
+    "flags": [ "CITY_UNIQUE" ]
   },
   {
     "type": "city_building",
@@ -3236,7 +3242,8 @@
       { "point": [ 1, 1, 0 ], "overmap": "mall_a_80_south" },
       { "point": [ 0, 1, 0 ], "overmap": "mall_a_81_south" }
     ],
-    "city_sizes": [ 16, -1 ]
+    "city_sizes": [ 16, -1 ],
+    "flags": [ "CITY_UNIQUE" ]
   },
   {
     "type": "city_building",
@@ -3485,7 +3492,8 @@
       { "point": [ 2, 1, 3 ], "overmap": "stadium_2_1_3_north" },
       { "point": [ 0, 3, 3 ], "overmap": "stadium_0_3_3_north" }
     ],
-    "city_sizes": [ 16, -1 ]
+    "city_sizes": [ 16, -1 ],
+    "flags": [ "CITY_UNIQUE" ]
   },
   {
     "type": "city_building",
@@ -3638,7 +3646,8 @@
       { "point": [ 5, 5, 5 ], "overmap": "stadium_football_5_5_5_north" },
       { "point": [ 6, 5, 5 ], "overmap": "stadium_football_6_5_5_north" }
     ],
-    "city_sizes": [ 16, -1 ]
+    "city_sizes": [ 16, -1 ],
+    "flags": [ "CITY_UNIQUE" ]
   },
   {
     "type": "city_building",
@@ -3735,7 +3744,8 @@
       { "point": [ 0, 1, 2 ], "overmap": "town_hall_0_1_roof_north" },
       { "point": [ 1, 1, 2 ], "overmap": "town_hall_1_1_roof_north" }
     ],
-    "city_sizes": [ 10, -1 ]
+    "city_sizes": [ 10, -1 ],
+    "flags": [ "CITY_UNIQUE" ]
   },
   {
     "type": "city_building",
diff --git a/data/json/overmap/overmap_mutable/anthill.json b/data/json/overmap/overmap_mutable/anthill.json
index 8150847e16a5e..c7c9be0f1712d 100644
--- a/data/json/overmap/overmap_mutable/anthill.json
+++ b/data/json/overmap/overmap_mutable/anthill.json
@@ -18,7 +18,7 @@
     "locations": [ "subterranean_empty" ],
     "city_distance": [ 10, -1 ],
     "occurrences": [ 80, 100 ],
-    "flags": [ "ANT", "UNIQUE", "WILDERNESS" ],
+    "flags": [ "ANT", "OVERMAP_UNIQUE", "WILDERNESS" ],
     "spawns": { "group": "GROUP_ANT_SURFACE", "population": [ 1000, 2000 ], "radius": [ 10, 30 ] },
     "check_for_locations": [
       [ [ 0, 0, 0 ], [ "land", "agricultural" ] ],
@@ -91,7 +91,7 @@
     "locations": [ "subterranean_empty" ],
     "city_distance": [ 10, -1 ],
     "occurrences": [ 80, 100 ],
-    "flags": [ "ANT", "UNIQUE", "WILDERNESS" ],
+    "flags": [ "ANT", "OVERMAP_UNIQUE", "WILDERNESS" ],
     "spawns": { "group": "GROUP_ACID_ANT_SURFACE", "population": [ 1000, 2000 ], "radius": [ 10, 30 ] },
     "check_for_locations": [
       [ [ 0, 0, 0 ], [ "land", "agricultural" ] ],
diff --git a/data/json/overmap/overmap_mutable/crater.json b/data/json/overmap/overmap_mutable/crater.json
index 29b050474a012..c88952ca9ddd4 100644
--- a/data/json/overmap/overmap_mutable/crater.json
+++ b/data/json/overmap/overmap_mutable/crater.json
@@ -7,7 +7,7 @@
     "occurrences": [ 66, 100 ],
     "//": "Spawn after all roads from other specials to avoid their roads routing around placed craters",
     "priority": -2,
-    "flags": [ "UNIQUE", "BLOB", "CLASSIC" ],
+    "flags": [ "OVERMAP_UNIQUE", "BLOB", "CLASSIC" ],
     "check_for_locations_area": [ { "type": [ "land", "road", "agricultural" ], "from": [ -1, -1, 0 ], "to": [ 1, 1, 0 ] } ],
     "joins": [ "crater_to_crater", "root" ],
     "overmaps": {
diff --git a/data/json/overmap/overmap_mutable/farm_horse_mutable.json b/data/json/overmap/overmap_mutable/farm_horse_mutable.json
index 21b7819624d63..bae9becfde331 100644
--- a/data/json/overmap/overmap_mutable/farm_horse_mutable.json
+++ b/data/json/overmap/overmap_mutable/farm_horse_mutable.json
@@ -7,7 +7,7 @@
     "city_distance": [ 5, -1 ],
     "city_sizes": [ 1, -1 ],
     "occurrences": [ 80, 100 ],
-    "flags": [ "CLASSIC", "MAN_MADE", "FARM", "UNIQUE" ],
+    "flags": [ "CLASSIC", "MAN_MADE", "FARM", "OVERMAP_UNIQUE" ],
     "check_for_locations_area": [ { "type": [ "forest_without_trail", "field" ], "from": [ -6, -2, 0 ], "to": [ 7, 9, 0 ] } ],
     "joins": [
       "root_to_road",
diff --git a/data/json/overmap/overmap_special/alien.json b/data/json/overmap/overmap_special/alien.json
index 073e18bfc7bdc..0d78f1daade60 100644
--- a/data/json/overmap/overmap_special/alien.json
+++ b/data/json/overmap/overmap_special/alien.json
@@ -12,7 +12,7 @@
     "city_distance": [ 0, 30 ],
     "city_sizes": [ 0, 16 ],
     "occurrences": [ 2, 100 ],
-    "flags": [ "EXODII", "CBM", "UNIQUE" ]
+    "flags": [ "EXODII", "CBM", "OVERMAP_UNIQUE" ]
   },
   {
     "type": "overmap_special",
diff --git a/data/json/overmap/overmap_special/campus.json b/data/json/overmap/overmap_special/campus.json
index 3abdeb3a8557a..e8286c9f35ac3 100644
--- a/data/json/overmap/overmap_special/campus.json
+++ b/data/json/overmap/overmap_special/campus.json
@@ -125,7 +125,7 @@
     "city_distance": [ 3, -1 ],
     "city_sizes": [ 1, 16 ],
     "occurrences": [ 0, 0 ],
-    "flags": [ "UNIQUE", "MAN_MADE" ]
+    "flags": [ "OVERMAP_UNIQUE", "MAN_MADE" ]
   },
   {
     "type": "overmap_special",
@@ -152,7 +152,7 @@
     "city_distance": [ 3, -1 ],
     "city_sizes": [ 1, 16 ],
     "occurrences": [ 0, 0 ],
-    "flags": [ "UNIQUE", "MAN_MADE" ]
+    "flags": [ "OVERMAP_UNIQUE", "MAN_MADE" ]
   },
   {
     "type": "overmap_special",
@@ -195,7 +195,7 @@
     "city_distance": [ 3, -1 ],
     "city_sizes": [ 1, 16 ],
     "occurrences": [ 0, 0 ],
-    "flags": [ "UNIQUE", "MAN_MADE" ]
+    "flags": [ "OVERMAP_UNIQUE", "MAN_MADE" ]
   },
   {
     "type": "overmap_special",
@@ -226,7 +226,7 @@
     "city_distance": [ 3, -1 ],
     "city_sizes": [ 1, 16 ],
     "occurrences": [ 0, 0 ],
-    "flags": [ "UNIQUE", "MAN_MADE" ]
+    "flags": [ "OVERMAP_UNIQUE", "MAN_MADE" ]
   },
   {
     "type": "overmap_special",
@@ -249,6 +249,6 @@
     "city_distance": [ 3, -1 ],
     "city_sizes": [ 1, 16 ],
     "occurrences": [ 0, 0 ],
-    "flags": [ "UNIQUE", "MAN_MADE" ]
+    "flags": [ "OVERMAP_UNIQUE", "MAN_MADE" ]
   }
 ]
diff --git a/data/json/overmap/overmap_special/lab_modular/lab_mutagen_6_floor.json b/data/json/overmap/overmap_special/lab_modular/lab_mutagen_6_floor.json
index c39586b8e693d..b607062081fa5 100644
--- a/data/json/overmap/overmap_special/lab_modular/lab_mutagen_6_floor.json
+++ b/data/json/overmap/overmap_special/lab_modular/lab_mutagen_6_floor.json
@@ -132,6 +132,6 @@
     "city_distance": [ 3, -1 ],
     "city_sizes": [ 1, 16 ],
     "occurrences": [ 30, 100 ],
-    "flags": [ "UNIQUE", "MAN_MADE" ]
+    "flags": [ "OVERMAP_UNIQUE", "MAN_MADE" ]
   }
 ]
diff --git a/data/json/overmap/overmap_special/oil_platform.json b/data/json/overmap/overmap_special/oil_platform.json
index 1c77bbf07f65b..e53240786edcd 100644
--- a/data/json/overmap/overmap_special/oil_platform.json
+++ b/data/json/overmap/overmap_special/oil_platform.json
@@ -211,6 +211,6 @@
     "city_distance": [ 150, 1000 ],
     "locations": [ "ocean_surface" ],
     "occurrences": [ 5, 100 ],
-    "flags": [ "MAN_MADE", "OCEAN", "UNIQUE" ]
+    "flags": [ "MAN_MADE", "OCEAN", "OVERMAP_UNIQUE" ]
   }
 ]
diff --git a/data/json/overmap/overmap_special/specials.json b/data/json/overmap/overmap_special/specials.json
index fcd5ecfa61fc1..4e4959b19f2e5 100644
--- a/data/json/overmap/overmap_special/specials.json
+++ b/data/json/overmap/overmap_special/specials.json
@@ -356,7 +356,7 @@
     "city_distance": [ 25, -1 ],
     "city_sizes": [ 0, 12 ],
     "occurrences": [ 20, 100 ],
-    "flags": [ "CLASSIC", "MAN_MADE", "UNIQUE", "WILDERNESS" ]
+    "flags": [ "CLASSIC", "MAN_MADE", "OVERMAP_UNIQUE", "WILDERNESS" ]
   },
   {
     "type": "overmap_special",
@@ -384,7 +384,7 @@
     "city_distance": [ 25, -1 ],
     "city_sizes": [ 0, 12 ],
     "occurrences": [ 20, 100 ],
-    "flags": [ "CLASSIC", "MAN_MADE", "UNIQUE", "WILDERNESS" ]
+    "flags": [ "CLASSIC", "MAN_MADE", "OVERMAP_UNIQUE", "WILDERNESS" ]
   },
   {
     "type": "overmap_special",
@@ -461,7 +461,7 @@
     "locations": [ "wilderness" ],
     "city_distance": [ 10, -1 ],
     "occurrences": [ 80, 100 ],
-    "flags": [ "BEE", "UNIQUE", "WILDERNESS" ],
+    "flags": [ "BEE", "OVERMAP_UNIQUE", "WILDERNESS" ],
     "spawns": { "group": "GROUP_BEE", "population": [ 100, 120 ], "radius": [ 10, 12 ] }
   },
   {
@@ -496,7 +496,7 @@
     "city_distance": [ 30, -1 ],
     "city_sizes": [ 0, 12 ],
     "occurrences": [ 10, 100 ],
-    "flags": [ "CLASSIC", "MAN_MADE", "UNIQUE" ]
+    "flags": [ "CLASSIC", "MAN_MADE", "OVERMAP_UNIQUE" ]
   },
   {
     "type": "overmap_special",
@@ -594,7 +594,7 @@
     "locations": [ "field", "forest_without_trail" ],
     "city_sizes": [ 1, 12 ],
     "occurrences": [ 5, 100 ],
-    "flags": [ "CLASSIC", "UNIQUE", "MAN_MADE" ]
+    "flags": [ "CLASSIC", "OVERMAP_UNIQUE", "MAN_MADE" ]
   },
   {
     "type": "overmap_special",
@@ -725,7 +725,7 @@
     "city_distance": [ 25, -1 ],
     "occurrences": [ 50, 100 ],
     "//": "Inflated chance, effective rate ~40%",
-    "flags": [ "WILDERNESS", "UNIQUE", "MAN_MADE" ]
+    "flags": [ "WILDERNESS", "OVERMAP_UNIQUE", "MAN_MADE" ]
   },
   {
     "type": "overmap_special",
@@ -759,7 +759,7 @@
     "locations": [ "forest" ],
     "city_distance": [ 25, -1 ],
     "occurrences": [ 20, 100 ],
-    "flags": [ "WILDERNESS", "UNIQUE", "MAN_MADE" ]
+    "flags": [ "WILDERNESS", "OVERMAP_UNIQUE", "MAN_MADE" ]
   },
   {
     "type": "overmap_special",
@@ -768,7 +768,7 @@
     "locations": [ "forest_center" ],
     "city_distance": [ 10, 80 ],
     "occurrences": [ 75, 100 ],
-    "flags": [ "CLASSIC", "WILDERNESS", "UNIQUE", "MAN_MADE" ]
+    "flags": [ "CLASSIC", "WILDERNESS", "OVERMAP_UNIQUE", "MAN_MADE" ]
   },
   {
     "type": "overmap_special",
@@ -799,7 +799,7 @@
     "locations": [ "forest" ],
     "city_distance": [ 40, -1 ],
     "occurrences": [ 10, 100 ],
-    "flags": [ "WILDERNESS", "UNIQUE" ]
+    "flags": [ "WILDERNESS", "OVERMAP_UNIQUE" ]
   },
   {
     "type": "overmap_special",
@@ -810,7 +810,7 @@
     "city_distance": [ 40, -1 ],
     "occurrences": [ 10, 100 ],
     "rotate": false,
-    "flags": [ "CLASSIC", "WILDERNESS", "UNIQUE" ]
+    "flags": [ "CLASSIC", "WILDERNESS", "OVERMAP_UNIQUE" ]
   },
   {
     "type": "overmap_special",
@@ -820,7 +820,7 @@
     "locations": [ "field", "forest_without_trail" ],
     "city_distance": [ 10, -1 ],
     "occurrences": [ 2, 100 ],
-    "flags": [ "LAB", "UNIQUE", "MAN_MADE" ]
+    "flags": [ "LAB", "OVERMAP_UNIQUE", "MAN_MADE" ]
   },
   {
     "type": "overmap_special",
@@ -834,7 +834,7 @@
     "locations": [ "field", "forest_without_trail" ],
     "city_distance": [ 10, -1 ],
     "occurrences": [ 2, 100 ],
-    "flags": [ "ANT", "UNIQUE", "MAN_MADE" ],
+    "flags": [ "ANT", "OVERMAP_UNIQUE", "MAN_MADE" ],
     "spawns": { "group": "GROUP_ANT_SURFACE", "population": [ 1000, 2000 ], "radius": [ 10, 30 ] }
   },
   {
@@ -885,7 +885,7 @@
     "city_distance": [ 15, -1 ],
     "priority": 1,
     "occurrences": [ 2, 100 ],
-    "flags": [ "UNIQUE", "LAB", "WILDERNESS", "MAN_MADE" ],
+    "flags": [ "OVERMAP_UNIQUE", "LAB", "WILDERNESS", "MAN_MADE" ],
     "rotate": false
   },
   {
@@ -896,7 +896,7 @@
     "locations": [ "field", "forest_without_trail" ],
     "city_distance": [ 10, -1 ],
     "occurrences": [ 2, 100 ],
-    "flags": [ "LAB", "UNIQUE", "MAN_MADE" ]
+    "flags": [ "LAB", "OVERMAP_UNIQUE", "MAN_MADE" ]
   },
   {
     "type": "overmap_special",
@@ -955,7 +955,7 @@
     "locations": [ "forest" ],
     "city_distance": [ 20, -1 ],
     "occurrences": [ 5, 100 ],
-    "flags": [ "MILITARY", "UNIQUE", "MAN_MADE" ]
+    "flags": [ "MILITARY", "OVERMAP_UNIQUE", "MAN_MADE" ]
   },
   {
     "type": "overmap_special",
@@ -964,7 +964,7 @@
     "locations": [ "field", "forest_without_trail" ],
     "city_distance": [ 15, -1 ],
     "occurrences": [ 5, 100 ],
-    "flags": [ "MILITARY", "UNIQUE", "WILDERNESS", "MAN_MADE" ]
+    "flags": [ "MILITARY", "OVERMAP_UNIQUE", "WILDERNESS", "MAN_MADE" ]
   },
   {
     "type": "overmap_special",
@@ -976,7 +976,7 @@
     "locations": [ "field", "forest_without_trail" ],
     "city_distance": [ 15, -1 ],
     "occurrences": [ 5, 100 ],
-    "flags": [ "MILITARY", "UNIQUE", "WILDERNESS", "MAN_MADE" ]
+    "flags": [ "MILITARY", "OVERMAP_UNIQUE", "WILDERNESS", "MAN_MADE" ]
   },
   {
     "type": "overmap_special",
@@ -996,7 +996,7 @@
     "city_distance": [ 30, -1 ],
     "city_sizes": [ -1, 4 ],
     "occurrences": [ 10, 100 ],
-    "flags": [ "MILITARY", "UNIQUE", "MAN_MADE" ]
+    "flags": [ "MILITARY", "OVERMAP_UNIQUE", "MAN_MADE" ]
   },
   {
     "type": "overmap_special",
@@ -1102,7 +1102,7 @@
     "city_distance": [ 5, 25 ],
     "occurrences": [ 80, 100 ],
     "spawns": { "group": "GROUP_WASP_FORAGER", "population": [ 50, 80 ], "radius": [ 6, 20 ] },
-    "flags": [ "UNIQUE", "MAN_MADE" ]
+    "flags": [ "OVERMAP_UNIQUE", "MAN_MADE" ]
   },
   {
     "type": "overmap_special",
@@ -1123,7 +1123,7 @@
     "city_distance": [ 5, 25 ],
     "occurrences": [ 80, 100 ],
     "spawns": { "group": "GROUP_WASP_FORAGER", "population": [ 50, 100 ], "radius": [ 6, 20 ] },
-    "flags": [ "UNIQUE", "MAN_MADE" ]
+    "flags": [ "OVERMAP_UNIQUE", "MAN_MADE" ]
   },
   {
     "type": "overmap_special",
@@ -1172,7 +1172,7 @@
     "city_distance": [ 5, 40 ],
     "city_sizes": [ 4, -1 ],
     "occurrences": [ 50, 100 ],
-    "flags": [ "CLASSIC", "UNIQUE", "MAN_MADE" ]
+    "flags": [ "CLASSIC", "OVERMAP_UNIQUE", "MAN_MADE" ]
   },
   {
     "type": "overmap_special",
@@ -1308,7 +1308,7 @@
     "city_distance": [ 3, -1 ],
     "city_sizes": [ 4, 12 ],
     "occurrences": [ 50, 100 ],
-    "flags": [ "CLASSIC", "LAKE", "UNIQUE", "MAN_MADE" ]
+    "flags": [ "CLASSIC", "LAKE", "OVERMAP_UNIQUE", "MAN_MADE" ]
   },
   {
     "type": "overmap_special",
@@ -1444,7 +1444,7 @@
     "city_distance": [ 3, -1 ],
     "city_sizes": [ 4, 12 ],
     "occurrences": [ 50, 100 ],
-    "flags": [ "CLASSIC", "LAKE", "UNIQUE", "MAN_MADE" ]
+    "flags": [ "CLASSIC", "LAKE", "OVERMAP_UNIQUE", "MAN_MADE" ]
   },
   {
     "type": "overmap_special",
@@ -1493,7 +1493,7 @@
     "city_distance": [ 10, 40 ],
     "city_sizes": [ 4, -1 ],
     "occurrences": [ 2, 100 ],
-    "flags": [ "LAB", "UNIQUE", "MAN_MADE" ]
+    "flags": [ "LAB", "OVERMAP_UNIQUE", "MAN_MADE" ]
   },
   {
     "type": "overmap_special",
@@ -1506,7 +1506,7 @@
     "city_sizes": [ 0, 12 ],
     "occurrences": [ 33, 100 ],
     "rotate": false,
-    "flags": [ "WILDERNESS", "UNIQUE" ]
+    "flags": [ "WILDERNESS", "OVERMAP_UNIQUE" ]
   },
   {
     "type": "overmap_special",
@@ -1526,7 +1526,7 @@
     "locations": [ "wilderness" ],
     "city_distance": [ 5, -1 ],
     "occurrences": [ 90, 100 ],
-    "flags": [ "FUNGAL", "UNIQUE", "WILDERNESS" ],
+    "flags": [ "FUNGAL", "OVERMAP_UNIQUE", "WILDERNESS" ],
     "rotate": false,
     "spawns": { "group": "GROUP_FUNGI", "population": [ 600, 1200 ], "radius": [ 30, 50 ] }
   },
@@ -1537,7 +1537,7 @@
     "locations": [ "wilderness" ],
     "city_distance": [ 5, -1 ],
     "occurrences": [ 90, 100 ],
-    "flags": [ "FUNGAL", "UNIQUE", "WILDERNESS" ],
+    "flags": [ "FUNGAL", "OVERMAP_UNIQUE", "WILDERNESS" ],
     "rotate": false,
     "spawns": { "group": "GROUP_FUNGI_TOWER", "population": [ 125, 175 ], "radius": [ 2, 2 ] }
   },
@@ -1548,7 +1548,7 @@
     "locations": [ "land" ],
     "city_distance": [ 5, -1 ],
     "occurrences": [ 90, 100 ],
-    "flags": [ "FUNGAL", "UNIQUE", "WILDERNESS" ],
+    "flags": [ "FUNGAL", "OVERMAP_UNIQUE", "WILDERNESS" ],
     "rotate": false,
     "spawns": { "group": "GROUP_FUNGI_FLOWERS", "population": [ 50, 100 ], "radius": [ 2, 4 ] }
   },
@@ -1931,7 +1931,7 @@
     "locations": [ "forest" ],
     "city_distance": [ 8, -1 ],
     "occurrences": [ 10, 100 ],
-    "flags": [ "WILDERNESS", "UNIQUE" ]
+    "flags": [ "WILDERNESS", "OVERMAP_UNIQUE" ]
   },
   {
     "type": "overmap_special",
@@ -1962,7 +1962,7 @@
     "city_distance": [ 15, -1 ],
     "city_sizes": [ 6, -1 ],
     "occurrences": [ 5, 100 ],
-    "flags": [ "UNIQUE", "MAN_MADE" ]
+    "flags": [ "OVERMAP_UNIQUE", "MAN_MADE" ]
   },
   {
     "type": "overmap_special",
@@ -2505,7 +2505,7 @@
     "city_distance": [ 20, -1 ],
     "city_sizes": [ 4, -1 ],
     "occurrences": [ 80, 100 ],
-    "flags": [ "CLASSIC", "WILDERNESS", "UNIQUE", "SAFE_AT_WORLDGEN", "MAN_MADE" ]
+    "flags": [ "CLASSIC", "WILDERNESS", "OVERMAP_UNIQUE", "SAFE_AT_WORLDGEN", "MAN_MADE" ]
   },
   {
     "type": "overmap_special",
@@ -2525,7 +2525,7 @@
     "city_distance": [ 20, -1 ],
     "city_sizes": [ 4, -1 ],
     "occurrences": [ 50, 100 ],
-    "flags": [ "CLASSIC", "WILDERNESS", "UNIQUE", "SAFE_AT_WORLDGEN", "MAN_MADE" ]
+    "flags": [ "CLASSIC", "WILDERNESS", "OVERMAP_UNIQUE", "SAFE_AT_WORLDGEN", "MAN_MADE" ]
   },
   {
     "type": "overmap_special",
@@ -2538,7 +2538,7 @@
     "city_distance": [ 20, 60 ],
     "city_sizes": [ 8, -1 ],
     "occurrences": [ 10, 100 ],
-    "flags": [ "CLASSIC", "WILDERNESS", "SAFE_AT_WORLDGEN", "UNIQUE", "MAN_MADE" ]
+    "flags": [ "CLASSIC", "WILDERNESS", "SAFE_AT_WORLDGEN", "OVERMAP_UNIQUE", "MAN_MADE" ]
   },
   {
     "type": "overmap_special",
@@ -2560,7 +2560,7 @@
     "city_distance": [ 20, -1 ],
     "city_sizes": [ 4, -1 ],
     "occurrences": [ 10, 100 ],
-    "flags": [ "CLASSIC", "WILDERNESS", "UNIQUE", "SAFE_AT_WORLDGEN", "MAN_MADE" ]
+    "flags": [ "CLASSIC", "WILDERNESS", "OVERMAP_UNIQUE", "SAFE_AT_WORLDGEN", "MAN_MADE" ]
   },
   {
     "type": "overmap_special",
@@ -2722,7 +2722,7 @@
     "locations": [ "wilderness" ],
     "city_distance": [ 3, -1 ],
     "occurrences": [ 30, 100 ],
-    "flags": [ "UNIQUE", "SAFE_AT_WORLDGEN", "MAN_MADE", "FARM" ]
+    "flags": [ "OVERMAP_UNIQUE", "SAFE_AT_WORLDGEN", "MAN_MADE", "FARM" ]
   },
   {
     "type": "overmap_special",
@@ -2896,7 +2896,7 @@
     "locations": [ "field" ],
     "city_distance": [ 15, -1 ],
     "occurrences": [ 5, 100 ],
-    "flags": [ "CLASSIC", "WILDERNESS", "UNIQUE" ]
+    "flags": [ "CLASSIC", "WILDERNESS", "OVERMAP_UNIQUE" ]
   },
   {
     "type": "overmap_special",
@@ -3059,7 +3059,7 @@
     "city_distance": [ 0, 10 ],
     "city_sizes": [ 6, -1 ],
     "occurrences": [ 85, 100 ],
-    "flags": [ "UNIQUE", "CLASSIC", "MAN_MADE" ]
+    "flags": [ "OVERMAP_UNIQUE", "CLASSIC", "MAN_MADE" ]
   },
   {
     "type": "overmap_special",
@@ -3108,7 +3108,7 @@
     "locations": [ "land" ],
     "city_distance": [ 15, 50 ],
     "occurrences": [ 60, 100 ],
-    "flags": [ "UNIQUE", "CLASSIC", "MAN_MADE" ]
+    "flags": [ "OVERMAP_UNIQUE", "CLASSIC", "MAN_MADE" ]
   },
   {
     "type": "overmap_special",
@@ -3158,7 +3158,7 @@
     "city_distance": [ 0, 10 ],
     "city_sizes": [ 6, -1 ],
     "occurrences": [ 70, 100 ],
-    "flags": [ "UNIQUE", "CLASSIC", "MAN_MADE" ]
+    "flags": [ "OVERMAP_UNIQUE", "CLASSIC", "MAN_MADE" ]
   },
   {
     "type": "overmap_special",
@@ -3207,7 +3207,7 @@
     "locations": [ "land" ],
     "city_distance": [ 15, 50 ],
     "occurrences": [ 30, 100 ],
-    "flags": [ "UNIQUE", "CLASSIC", "MAN_MADE" ]
+    "flags": [ "OVERMAP_UNIQUE", "CLASSIC", "MAN_MADE" ]
   },
   {
     "type": "overmap_special",
@@ -3255,7 +3255,7 @@
     "locations": [ "land" ],
     "city_distance": [ 20, 60 ],
     "occurrences": [ 15, 100 ],
-    "flags": [ "UNIQUE", "CLASSIC", "MAN_MADE" ]
+    "flags": [ "OVERMAP_UNIQUE", "CLASSIC", "MAN_MADE" ]
   },
   {
     "type": "overmap_special",
@@ -3379,7 +3379,7 @@
     "city_distance": [ 20, -1 ],
     "city_sizes": [ 4, -1 ],
     "occurrences": [ 50, 100 ],
-    "flags": [ "CLASSIC", "URBAN", "UNIQUE", "MAN_MADE" ]
+    "flags": [ "CLASSIC", "URBAN", "OVERMAP_UNIQUE", "MAN_MADE" ]
   },
   {
     "type": "overmap_special",
@@ -3576,7 +3576,7 @@
     "city_distance": [ 20, 60 ],
     "city_sizes": [ 8, -1 ],
     "occurrences": [ 1, 5 ],
-    "flags": [ "UNIQUE", "CLASSIC", "WILDERNESS", "MAN_MADE" ]
+    "flags": [ "OVERMAP_UNIQUE", "CLASSIC", "WILDERNESS", "MAN_MADE" ]
   },
   {
     "type": "overmap_special",
@@ -3699,7 +3699,7 @@
     "city_sizes": [ 1, 16 ],
     "occurrences": [ 33, 100 ],
     "rotate": false,
-    "flags": [ "UNIQUE", "SAFE_AT_WORLDGEN", "MAN_MADE", "GLOBALLY_UNIQUE" ]
+    "flags": [ "OVERMAP_UNIQUE", "SAFE_AT_WORLDGEN", "MAN_MADE", "GLOBALLY_UNIQUE" ]
   },
   {
     "type": "overmap_special",
@@ -3782,7 +3782,7 @@
     "locations": [ "land" ],
     "city_distance": [ 5, -1 ],
     "occurrences": [ 50, 100 ],
-    "flags": [ "LAB", "MAN_MADE", "UNIQUE" ]
+    "flags": [ "LAB", "MAN_MADE", "OVERMAP_UNIQUE" ]
   },
   {
     "type": "overmap_special",
@@ -3799,7 +3799,7 @@
     "city_distance": [ 1, -1 ],
     "occurrences": [ 2, 2 ],
     "rotate": false,
-    "flags": [ "UNIQUE" ]
+    "flags": [ "OVERMAP_UNIQUE" ]
   },
   {
     "type": "overmap_special",
@@ -3845,7 +3845,7 @@
     "city_distance": [ 5, -1 ],
     "connections": [ { "point": [ 2, -2, -1 ], "terrain": "sewer", "connection": "sewer_tunnel", "from": [ 2, -1, -1 ] } ],
     "occurrences": [ 20, 100 ],
-    "flags": [ "LAB", "UNIQUE", "MAN_MADE" ]
+    "flags": [ "LAB", "OVERMAP_UNIQUE", "MAN_MADE" ]
   },
   {
     "type": "overmap_special",
@@ -3895,7 +3895,7 @@
     "locations": [ "field", "forest_without_trail" ],
     "city_distance": [ 10, -1 ],
     "occurrences": [ 30, 100 ],
-    "flags": [ "LAB", "UNIQUE", "MAN_MADE" ]
+    "flags": [ "LAB", "OVERMAP_UNIQUE", "MAN_MADE" ]
   },
   {
     "type": "overmap_special",
@@ -3947,7 +3947,7 @@
     "city_distance": [ 10, -1 ],
     "occurrences": [ 30, 100 ],
     "rotate": false,
-    "flags": [ "LAB", "UNIQUE", "MAN_MADE" ]
+    "flags": [ "LAB", "OVERMAP_UNIQUE", "MAN_MADE" ]
   },
   {
     "type": "overmap_special",
@@ -4056,7 +4056,7 @@
     "locations": [ "land" ],
     "city_distance": [ 5, -1 ],
     "occurrences": [ 50, 100 ],
-    "flags": [ "LAB", "MAN_MADE", "UNIQUE" ]
+    "flags": [ "LAB", "MAN_MADE", "OVERMAP_UNIQUE" ]
   },
   {
     "type": "overmap_special",
@@ -4076,7 +4076,7 @@
     "city_distance": [ 10, -1 ],
     "rotate": false,
     "occurrences": [ 10, 100 ],
-    "flags": [ "LAB", "UNIQUE", "MAN_MADE" ]
+    "flags": [ "LAB", "OVERMAP_UNIQUE", "MAN_MADE" ]
   },
   {
     "type": "overmap_special",
@@ -4088,7 +4088,7 @@
     "locations": [ "forest" ],
     "city_distance": [ 25, -1 ],
     "occurrences": [ 40, 100 ],
-    "flags": [ "CLASSIC", "UNIQUE", "MAN_MADE", "WILDERNESS" ]
+    "flags": [ "CLASSIC", "OVERMAP_UNIQUE", "MAN_MADE", "WILDERNESS" ]
   },
   {
     "type": "overmap_special",
@@ -4097,7 +4097,7 @@
     "locations": [ "field" ],
     "city_distance": [ 25, -1 ],
     "occurrences": [ 40, 100 ],
-    "flags": [ "CLASSIC", "UNIQUE", "MAN_MADE", "WILDERNESS" ]
+    "flags": [ "CLASSIC", "OVERMAP_UNIQUE", "MAN_MADE", "WILDERNESS" ]
   },
   {
     "type": "overmap_special",
@@ -4109,7 +4109,7 @@
     "locations": [ "wilderness", "road", "agricultural" ],
     "city_distance": [ 15, -1 ],
     "occurrences": [ 10, 100 ],
-    "flags": [ "CLASSIC", "WILDERNESS", "UNIQUE" ]
+    "flags": [ "CLASSIC", "WILDERNESS", "OVERMAP_UNIQUE" ]
   },
   {
     "type": "overmap_special",
@@ -4186,7 +4186,7 @@
     "city_sizes": [ 6, -1 ],
     "occurrences": [ 40, 100 ],
     "//": "Inflated chance, in effect 15%",
-    "flags": [ "CLASSIC", "UNIQUE", "MAN_MADE" ]
+    "flags": [ "CLASSIC", "OVERMAP_UNIQUE", "MAN_MADE" ]
   },
   {
     "type": "overmap_special",
@@ -4349,7 +4349,7 @@
     "city_distance": [ 10, 120 ],
     "city_sizes": [ 4, -1 ],
     "occurrences": [ 30, 100 ],
-    "flags": [ "UNIQUE", "LAB", "MAN_MADE" ]
+    "flags": [ "OVERMAP_UNIQUE", "LAB", "MAN_MADE" ]
   },
   {
     "type": "overmap_special",
@@ -4387,7 +4387,7 @@
     "city_sizes": [ 6, -1 ],
     "occurrences": [ 70, 100 ],
     "//": "Inflated chance, effective rate ~40%",
-    "flags": [ "CLASSIC", "UNIQUE", "MAN_MADE" ]
+    "flags": [ "CLASSIC", "OVERMAP_UNIQUE", "MAN_MADE" ]
   },
   {
     "type": "overmap_special",
@@ -4426,7 +4426,7 @@
     "city_distance": [ 5, 40 ],
     "city_sizes": [ 8, -1 ],
     "occurrences": [ 50, 100 ],
-    "flags": [ "CLASSIC", "UNIQUE", "MAN_MADE" ]
+    "flags": [ "CLASSIC", "OVERMAP_UNIQUE", "MAN_MADE" ]
   },
   {
     "type": "overmap_special",
@@ -5338,7 +5338,7 @@
     "locations": [ "wilderness" ],
     "city_distance": [ 10, -1 ],
     "occurrences": [ 80, 100 ],
-    "flags": [ "MI-GO", "UNIQUE", "WILDERNESS" ],
+    "flags": [ "MI-GO", "OVERMAP_UNIQUE", "WILDERNESS" ],
     "spawns": { "group": "GROUP_MI-GO_CAMP_OM", "population": [ 20, 50 ], "radius": [ 2, 30 ] }
   },
   {
@@ -5383,7 +5383,7 @@
     "locations": [ "wilderness" ],
     "city_distance": [ 10, -1 ],
     "occurrences": [ 20, 100 ],
-    "flags": [ "MI-GO", "UNIQUE", "WILDERNESS" ]
+    "flags": [ "MI-GO", "OVERMAP_UNIQUE", "WILDERNESS" ]
   },
   {
     "type": "overmap_special",
@@ -6330,7 +6330,7 @@
     "priority": 1,
     "//": "Inflated chance, effective rate ~19% (n=726)",
     "connections": [ { "point": [ -1, 15, 0 ], "terrain": "road", "connection": "local_road" } ],
-    "flags": [ "FARM", "UNIQUE", "SAFE_AT_WORLDGEN", "MAN_MADE" ]
+    "flags": [ "FARM", "OVERMAP_UNIQUE", "SAFE_AT_WORLDGEN", "MAN_MADE" ]
   },
   {
     "id": "airliner_crashed",
@@ -6375,7 +6375,7 @@
     "locations": [ "land" ],
     "city_distance": [ 6, -1 ],
     "occurrences": [ 30, 100 ],
-    "flags": [ "CLASSIC", "WILDERNESS", "UNIQUE", "MAN_MADE" ]
+    "flags": [ "CLASSIC", "WILDERNESS", "OVERMAP_UNIQUE", "MAN_MADE" ]
   },
   {
     "type": "overmap_special",
@@ -6449,7 +6449,7 @@
     "city_sizes": [ 4, -1 ],
     "occurrences": [ 75, 100 ],
     "//": "Inflated chance, effective rate ~55%",
-    "flags": [ "CLASSIC", "UNIQUE", "MAN_MADE" ]
+    "flags": [ "CLASSIC", "OVERMAP_UNIQUE", "MAN_MADE" ]
   },
   {
     "type": "overmap_special",
@@ -6470,7 +6470,7 @@
     "city_distance": [ 10, 30 ],
     "city_sizes": [ 4, -1 ],
     "occurrences": [ 30, 100 ],
-    "flags": [ "CLASSIC", "UNIQUE", "MAN_MADE" ]
+    "flags": [ "CLASSIC", "OVERMAP_UNIQUE", "MAN_MADE" ]
   },
   {
     "type": "overmap_special",
@@ -6495,7 +6495,7 @@
     "city_distance": [ 10, 30 ],
     "city_sizes": [ 4, -1 ],
     "occurrences": [ 30, 100 ],
-    "flags": [ "CLASSIC", "UNIQUE", "MAN_MADE" ]
+    "flags": [ "CLASSIC", "OVERMAP_UNIQUE", "MAN_MADE" ]
   },
   {
     "type": "overmap_special",
@@ -6545,7 +6545,7 @@
     "city_sizes": [ 6, -1 ],
     "occurrences": [ 50, 100 ],
     "//": "Inflated chance, effective rate ~30%",
-    "flags": [ "CLASSIC", "URBAN", "UNIQUE", "MAN_MADE" ]
+    "flags": [ "CLASSIC", "URBAN", "OVERMAP_UNIQUE", "MAN_MADE" ]
   },
   {
     "type": "overmap_special",
@@ -6569,7 +6569,7 @@
     "connections": [ { "point": [ 0, -1, 0 ], "terrain": "road", "connection": "local_road", "from": [ 0, 0, 0 ] } ],
     "city_distance": [ 10, -1 ],
     "occurrences": [ 5, 100 ],
-    "flags": [ "CLASSIC", "MILITARY", "UNIQUE", "MAN_MADE" ]
+    "flags": [ "CLASSIC", "MILITARY", "OVERMAP_UNIQUE", "MAN_MADE" ]
   },
   {
     "type": "overmap_special",
@@ -6856,7 +6856,7 @@
     "city_distance": [ 5, 40 ],
     "city_sizes": [ 8, -1 ],
     "occurrences": [ 50, 100 ],
-    "flags": [ "CLASSIC", "UNIQUE", "MAN_MADE" ]
+    "flags": [ "CLASSIC", "OVERMAP_UNIQUE", "MAN_MADE" ]
   },
   {
     "type": "overmap_special",
@@ -6921,7 +6921,7 @@
     "city_distance": [ 1, 40 ],
     "city_sizes": [ 6, -1 ],
     "occurrences": [ 5, 100 ],
-    "flags": [ "CLASSIC", "UNIQUE", "MAN_MADE" ]
+    "flags": [ "CLASSIC", "OVERMAP_UNIQUE", "MAN_MADE" ]
   },
   {
     "type": "overmap_special",
@@ -6981,7 +6981,7 @@
     "city_distance": [ 0, 100 ],
     "city_sizes": [ 0, 12 ],
     "occurrences": [ 5, 100 ],
-    "flags": [ "CLASSIC", "UNIQUE", "MAN_MADE", "WILDERNESS" ]
+    "flags": [ "CLASSIC", "OVERMAP_UNIQUE", "MAN_MADE", "WILDERNESS" ]
   },
   {
     "type": "overmap_special",
@@ -7078,7 +7078,7 @@
     "//": "Low chance to find a matching location, so always try to place it",
     "occurrences": [ 99, 100 ],
     "priority": 1,
-    "flags": [ "LAB", "UNIQUE", "MAN_MADE" ]
+    "flags": [ "LAB", "OVERMAP_UNIQUE", "MAN_MADE" ]
   },
   {
     "type": "overmap_special",
@@ -7121,7 +7121,7 @@
     "city_sizes": [ 1, 12 ],
     "occurrences": [ 5, 100 ],
     "priority": -1,
-    "flags": [ "CLASSIC", "UNIQUE", "MAN_MADE" ]
+    "flags": [ "CLASSIC", "OVERMAP_UNIQUE", "MAN_MADE" ]
   },
   {
     "type": "overmap_special",
@@ -7381,7 +7381,7 @@
     "city_distance": [ -1, 5 ],
     "city_sizes": [ 5, -1 ],
     "occurrences": [ 20, 100 ],
-    "flags": [ "UNIQUE", "SIDEWALK", "GENERIC_LOOT", "URBAN", "MAN_MADE" ]
+    "flags": [ "OVERMAP_UNIQUE", "SIDEWALK", "GENERIC_LOOT", "URBAN", "MAN_MADE" ]
   },
   {
     "type": "overmap_special",
@@ -7405,7 +7405,7 @@
     ],
     "locations": [ "field" ],
     "city_distance": [ 5, 40 ],
-    "flags": [ "CLASSIC", "MAN_MADE", "UNIQUE" ]
+    "flags": [ "CLASSIC", "MAN_MADE", "OVERMAP_UNIQUE" ]
   },
   {
     "type": "overmap_special",
@@ -7429,7 +7429,7 @@
     ],
     "locations": [ "field" ],
     "city_distance": [ 5, 40 ],
-    "flags": [ "CLASSIC", "MAN_MADE", "UNIQUE" ]
+    "flags": [ "CLASSIC", "MAN_MADE", "OVERMAP_UNIQUE" ]
   },
   {
     "type": "overmap_special",
@@ -7538,7 +7538,7 @@
     "locations": [ "land" ],
     "city_distance": [ 10, 40 ],
     "city_sizes": [ 5, -1 ],
-    "flags": [ "CLASSIC", "MAN_MADE", "UNIQUE" ]
+    "flags": [ "CLASSIC", "MAN_MADE", "OVERMAP_UNIQUE" ]
   },
   {
     "type": "overmap_special",
diff --git a/data/json/regional_map_settings.json b/data/json/regional_map_settings.json
index 99c4a568720f9..b4ebf983a6434 100644
--- a/data/json/regional_map_settings.json
+++ b/data/json/regional_map_settings.json
@@ -967,13 +967,13 @@
         "communitygarden_3": 75,
         "publicgarden": 100,
         "publicgarden_2": 100,
-        "cathedral": 10,
+        "cathedral": 50,
         "football_field": 25,
         "baseball_field": 50,
         "botanical_garden": 100,
         "zoo": 25,
-        "stadium": 25,
-        "stadium_football": 25,
+        "stadium": 50,
+        "stadium_football": 50,
         "convention_center": 10,
         "cemetery_city": 50,
         "public_pond_city": 50,
@@ -1177,19 +1177,19 @@
         "s_petstore": 100,
         "s_petstore_1": 100,
         "s_petstore_2": 100,
-        "megastore": 150,
+        "megastore": 250,
         "hotel_1": 75,
         "hotel_2": 75,
         "hotel_3": 75,
-        "hospital": 175,
-        "urban_35_hospital": 175,
+        "hospital": 250,
+        "urban_35_hospital": 200,
         "public_works": 200,
         "office_tower": 150,
         "office_tower_2": 150,
         "office_skyscraper": 300,
         "office_tower_large": 300,
         "office_tower_hiddenlab": 50,
-        "mall": 100,
+        "mall": 200,
         "home_improvement_superstore_new": 150,
         "lumberyard": 75,
         "landscaping_supply_co": 150,
diff --git a/data/mods/Aftershock/maps/overmap_specials.json b/data/mods/Aftershock/maps/overmap_specials.json
index a693bc18e471c..5a54eb138b4bb 100644
--- a/data/mods/Aftershock/maps/overmap_specials.json
+++ b/data/mods/Aftershock/maps/overmap_specials.json
@@ -167,7 +167,7 @@
     "city_distance": [ 20, -1 ],
     "city_sizes": [ 0, 12 ],
     "occurrences": [ 0, 0 ],
-    "flags": [ "UNIQUE", "MAN_MADE" ]
+    "flags": [ "OVERMAP_UNIQUE", "MAN_MADE" ]
   },
   {
     "type": "overmap_special",
diff --git a/data/mods/DinoMod/overmap/overmap_specials.json b/data/mods/DinoMod/overmap/overmap_specials.json
index d3b166556cf81..35e07875b2ce7 100644
--- a/data/mods/DinoMod/overmap/overmap_specials.json
+++ b/data/mods/DinoMod/overmap/overmap_specials.json
@@ -61,7 +61,7 @@
     "locations": [ "wilderness" ],
     "city_distance": [ 10, -1 ],
     "occurrences": [ 30, 100 ],
-    "flags": [ "LAB", "UNIQUE" ],
+    "flags": [ "LAB", "OVERMAP_UNIQUE" ],
     "rotate": false
   },
   {
diff --git a/data/mods/Magiclysm/worldgen/overmap_specials.json b/data/mods/Magiclysm/worldgen/overmap_specials.json
index 9baf26748c8e0..8ba75d9e858f3 100644
--- a/data/mods/Magiclysm/worldgen/overmap_specials.json
+++ b/data/mods/Magiclysm/worldgen/overmap_specials.json
@@ -239,7 +239,7 @@
     "city_sizes": [ 0, 20 ],
     "occurrences": [ 1, 2 ],
     "spawns": { "group": "GROUP_MAGIC_FIELD", "population": [ 2, 15 ], "radius": [ 1, 3 ] },
-    "flags": [ "UNIQUE" ]
+    "flags": [ "OVERMAP_UNIQUE" ]
   },
   {
     "type": "overmap_special",
@@ -259,7 +259,7 @@
     "city_distance": [ 20, -1 ],
     "city_sizes": [ 0, 20 ],
     "occurrences": [ 66, 100 ],
-    "flags": [ "UNIQUE" ]
+    "flags": [ "OVERMAP_UNIQUE" ]
   },
   {
     "type": "overmap_special",
diff --git a/data/mods/MindOverMatter/overmap/overmap_specials.json b/data/mods/MindOverMatter/overmap/overmap_specials.json
index c89964e9d8dc1..9562e9beb92b1 100644
--- a/data/mods/MindOverMatter/overmap/overmap_specials.json
+++ b/data/mods/MindOverMatter/overmap/overmap_specials.json
@@ -169,7 +169,7 @@
     "city_distance": [ 10, 120 ],
     "city_sizes": [ 4, -1 ],
     "occurrences": [ 30, 100 ],
-    "flags": [ "UNIQUE", "LAB", "MAN_MADE" ]
+    "flags": [ "OVERMAP_UNIQUE", "LAB", "MAN_MADE" ]
   },
   {
     "type": "overmap_special",
diff --git a/data/mods/No_Hope/overmap/overmap_specials.json b/data/mods/No_Hope/overmap/overmap_specials.json
index d8f54ec86def1..5c2e9a1440d62 100644
--- a/data/mods/No_Hope/overmap/overmap_specials.json
+++ b/data/mods/No_Hope/overmap/overmap_specials.json
@@ -12,7 +12,7 @@
     "city_distance": [ 25, -1 ],
     "city_sizes": [ 0, 12 ],
     "occurrences": [ 15, 100 ],
-    "flags": [ "CLASSIC", "MAN_MADE", "UNIQUE" ]
+    "flags": [ "CLASSIC", "MAN_MADE", "OVERMAP_UNIQUE" ]
   },
   {
     "type": "overmap_special",
@@ -26,7 +26,7 @@
     "city_distance": [ 25, -1 ],
     "city_sizes": [ 0, 12 ],
     "occurrences": [ 5, 100 ],
-    "flags": [ "CLASSIC", "MAN_MADE", "UNIQUE" ]
+    "flags": [ "CLASSIC", "MAN_MADE", "OVERMAP_UNIQUE" ]
   },
   {
     "//": "Military base is grossly unbalanced gameplay-wise, so until it gets some work done on this matter, I'm removing it from the game",
@@ -396,6 +396,6 @@
     "locations": [ "wilderness" ],
     "city_distance": [ 20, -1 ],
     "occurrences": [ 20, 100 ],
-    "flags": [ "UNIQUE" ]
+    "flags": [ "OVERMAP_UNIQUE" ]
   }
 ]
diff --git a/data/mods/TEST_DATA/overmap_specials.json b/data/mods/TEST_DATA/overmap_specials.json
index c00234fe1fda6..c2266a24c5e98 100644
--- a/data/mods/TEST_DATA/overmap_specials.json
+++ b/data/mods/TEST_DATA/overmap_specials.json
@@ -6,7 +6,7 @@
     "locations": [ "subterranean_empty" ],
     "city_distance": [ 10, -1 ],
     "occurrences": [ 80, 100 ],
-    "flags": [ "ANT", "UNIQUE", "CLASSIC", "WILDERNESS" ],
+    "flags": [ "ANT", "OVERMAP_UNIQUE", "CLASSIC", "WILDERNESS" ],
     "check_for_locations": [
       [ [ 0, 0, 0 ], [ "land" ] ],
       [ [ 0, 0, -1 ], [ "subterranean_empty" ] ],
diff --git a/data/mods/TropiCataclysm/overmap/overmap_mutable/termitemound.json b/data/mods/TropiCataclysm/overmap/overmap_mutable/termitemound.json
index eac69811c159c..0012b01f03776 100644
--- a/data/mods/TropiCataclysm/overmap/overmap_mutable/termitemound.json
+++ b/data/mods/TropiCataclysm/overmap/overmap_mutable/termitemound.json
@@ -12,7 +12,7 @@
     "locations": [ "subterranean_empty" ],
     "city_distance": [ 10, -1 ],
     "occurrences": [ 80, 100 ],
-    "flags": [ "UNIQUE", "CLASSIC", "WILDERNESS" ],
+    "flags": [ "OVERMAP_UNIQUE", "CLASSIC", "WILDERNESS" ],
     "spawns": { "group": "GROUP_TERMITE_SURFACE", "population": [ 1000, 2000 ], "radius": [ 10, 30 ] },
     "check_for_locations": [
       [ [ 0, 0, 0 ], [ "land" ] ],
diff --git a/data/mods/TropiCataclysm/overmap/overmap_special/specials.json b/data/mods/TropiCataclysm/overmap/overmap_special/specials.json
index 19b5f1c7ae662..43b06725b0ce2 100644
--- a/data/mods/TropiCataclysm/overmap/overmap_special/specials.json
+++ b/data/mods/TropiCataclysm/overmap/overmap_special/specials.json
@@ -6,7 +6,7 @@
     "locations": [ "wilderness" ],
     "city_distance": [ 5, -1 ],
     "occurrences": [ 90, 100 ],
-    "flags": [ "TRIFFID", "UNIQUE" ],
+    "flags": [ "TRIFFID", "OVERMAP_UNIQUE" ],
     "rotate": false,
     "spawns": { "group": "GROUP_TRIFFID_OUTER", "population": [ 125, 175 ], "radius": [ 2, 2 ] }
   },
@@ -17,7 +17,7 @@
     "locations": [ "wilderness" ],
     "city_distance": [ 5, -1 ],
     "occurrences": [ 90, 100 ],
-    "flags": [ "TRIFFID", "UNIQUE" ],
+    "flags": [ "TRIFFID", "OVERMAP_UNIQUE" ],
     "rotate": false,
     "spawns": { "group": "GROUP_TRIFFID_OUTER", "population": [ 100, 150 ], "radius": [ 2, 2 ] }
   },
@@ -28,7 +28,7 @@
     "locations": [ "wilderness" ],
     "city_distance": [ 5, -1 ],
     "occurrences": [ 90, 100 ],
-    "flags": [ "NETHER", "UNIQUE" ],
+    "flags": [ "NETHER", "OVERMAP_UNIQUE" ],
     "rotate": false,
     "spawns": { "group": "GROUP_ALIEN_REEF", "population": [ 100, 150 ], "radius": [ 2, 2 ] }
   }
diff --git a/data/mods/Xedra_Evolved/mapgen/overmap_special.json b/data/mods/Xedra_Evolved/mapgen/overmap_special.json
index d03bc0cdd302c..f1941ed21857d 100644
--- a/data/mods/Xedra_Evolved/mapgen/overmap_special.json
+++ b/data/mods/Xedra_Evolved/mapgen/overmap_special.json
@@ -130,7 +130,7 @@
     "city_distance": [ 5, -1 ],
     "city_sizes": [ 10, -1 ],
     "occurrences": [ 15, 100 ],
-    "flags": [ "UNIQUE", "MAN_MADE" ]
+    "flags": [ "OVERMAP_UNIQUE", "MAN_MADE" ]
   },
   {
     "type": "city_building",
@@ -181,7 +181,7 @@
     "city_distance": [ 20, -1 ],
     "city_sizes": [ 0, 20 ],
     "occurrences": [ 5, 100 ],
-    "flags": [ "UNIQUE", "WILDERNESS" ],
+    "flags": [ "OVERMAP_UNIQUE", "WILDERNESS" ],
     "spawns": { "group": "GROUP_GENIUS_IERDE", "population": [ 10, 30 ], "radius": [ 1, 3 ] }
   },
   {
@@ -201,7 +201,7 @@
     "city_distance": [ 20, -1 ],
     "city_sizes": [ 0, 20 ],
     "occurrences": [ 5, 100 ],
-    "flags": [ "UNIQUE", "WILDERNESS" ],
+    "flags": [ "OVERMAP_UNIQUE", "WILDERNESS" ],
     "spawns": { "group": "GROUP_GENIUS_ARVORE", "population": [ 10, 30 ], "radius": [ 1, 3 ] }
   },
   {
@@ -221,7 +221,7 @@
     "city_distance": [ 20, -1 ],
     "city_sizes": [ 0, 20 ],
     "occurrences": [ 5, 100 ],
-    "flags": [ "UNIQUE", "WILDERNESS" ],
+    "flags": [ "OVERMAP_UNIQUE", "WILDERNESS" ],
     "spawns": { "group": "GROUP_GENIUS_UNDINE", "population": [ 10, 30 ], "radius": [ 1, 3 ] }
   },
   {
@@ -241,7 +241,7 @@
     "city_distance": [ 20, -1 ],
     "city_sizes": [ 0, 20 ],
     "occurrences": [ 5, 100 ],
-    "flags": [ "UNIQUE", "WILDERNESS" ],
+    "flags": [ "OVERMAP_UNIQUE", "WILDERNESS" ],
     "spawns": { "group": "GROUP_GENIUS_SALAMANDER", "population": [ 10, 30 ], "radius": [ 1, 3 ] }
   },
   {
@@ -261,7 +261,7 @@
     "city_distance": [ 20, -1 ],
     "city_sizes": [ 0, 20 ],
     "occurrences": [ 5, 100 ],
-    "flags": [ "UNIQUE", "WILDERNESS" ],
+    "flags": [ "OVERMAP_UNIQUE", "WILDERNESS" ],
     "spawns": { "group": "GROUP_GENIUS_SYLPH", "population": [ 10, 30 ], "radius": [ 1, 3 ] }
   },
   {
@@ -281,7 +281,7 @@
     "city_distance": [ 20, -1 ],
     "city_sizes": [ 0, 20 ],
     "occurrences": [ 5, 100 ],
-    "flags": [ "UNIQUE", "WILDERNESS" ],
+    "flags": [ "OVERMAP_UNIQUE", "WILDERNESS" ],
     "spawns": { "group": "GROUP_GENIUS_HOMULLUS", "population": [ 10, 30 ], "radius": [ 1, 3 ] }
   },
   {
@@ -302,7 +302,7 @@
     "city_distance": [ 30, -1 ],
     "city_sizes": [ 0, 12 ],
     "occurrences": [ 5, 100 ],
-    "flags": [ "CLASSIC", "MAN_MADE", "UNIQUE" ]
+    "flags": [ "CLASSIC", "MAN_MADE", "OVERMAP_UNIQUE" ]
   },
   {
     "type": "overmap_special",
@@ -421,7 +421,7 @@
     "city_distance": [ 40, -1 ],
     "city_sizes": [ 0, 0 ],
     "occurrences": [ 66, 100 ],
-    "flags": [ "CLASSIC", "UNIQUE" ],
+    "flags": [ "CLASSIC", "OVERMAP_UNIQUE" ],
     "spawns": { "group": "GROUP_GENIUS_ARVORE", "population": [ 150, 500 ], "radius": [ 5, 30 ] }
   },
   {
@@ -444,6 +444,6 @@
     "city_distance": [ 30, -1 ],
     "city_sizes": [ 0, 12 ],
     "occurrences": [ 66, 100 ],
-    "flags": [ "CLASSIC", "UNIQUE" ]
+    "flags": [ "CLASSIC", "OVERMAP_UNIQUE" ]
   }
 ]
diff --git a/data/mods/innawood/overmap/specials_kept.json b/data/mods/innawood/overmap/specials_kept.json
index 8893446f6fda5..e82841c283548 100644
--- a/data/mods/innawood/overmap/specials_kept.json
+++ b/data/mods/innawood/overmap/specials_kept.json
@@ -13,7 +13,7 @@
     "locations": [ "forest" ],
     "city_distance": [ 40, -1 ],
     "occurrences": [ 10, 100 ],
-    "flags": [ "WILDERNESS", "UNIQUE" ]
+    "flags": [ "WILDERNESS", "OVERMAP_UNIQUE" ]
   },
   {
     "type": "overmap_special",
@@ -23,7 +23,7 @@
     "city_distance": [ 40, -1 ],
     "occurrences": [ 10, 100 ],
     "rotate": false,
-    "flags": [ "WILDERNESS", "UNIQUE" ]
+    "flags": [ "WILDERNESS", "OVERMAP_UNIQUE" ]
   },
   {
     "type": "overmap_special",
@@ -36,7 +36,7 @@
     "city_sizes": [ 0, 12 ],
     "occurrences": [ 33, 100 ],
     "rotate": false,
-    "flags": [ "WILDERNESS", "UNIQUE" ]
+    "flags": [ "WILDERNESS", "OVERMAP_UNIQUE" ]
   },
   {
     "type": "overmap_special",
@@ -74,7 +74,7 @@
     "locations": [ "forest" ],
     "city_distance": [ 8, -1 ],
     "occurrences": [ 10, 100 ],
-    "flags": [ "WILDERNESS", "UNIQUE" ]
+    "flags": [ "WILDERNESS", "OVERMAP_UNIQUE" ]
   },
   {
     "type": "overmap_special",
@@ -104,7 +104,7 @@
     "locations": [ "wilderness" ],
     "city_distance": [ 15, -1 ],
     "occurrences": [ 10, 100 ],
-    "flags": [ "CLASSIC", "WILDERNESS", "UNIQUE" ]
+    "flags": [ "CLASSIC", "WILDERNESS", "OVERMAP_UNIQUE" ]
   },
   {
     "type": "overmap_special",
diff --git a/data/mods/railroads/overmap/overmap_special/specials.json b/data/mods/railroads/overmap/overmap_special/specials.json
index e2b0822135e9d..4126876935b0d 100644
--- a/data/mods/railroads/overmap/overmap_special/specials.json
+++ b/data/mods/railroads/overmap/overmap_special/specials.json
@@ -38,6 +38,6 @@
     "city_sizes": [ 3, 12 ],
     "occurrences": [ 50, 100 ],
     "priority": 1,
-    "flags": [ "CLASSIC", "UNIQUE", "URBAN", "MAN_MADE" ]
+    "flags": [ "CLASSIC", "OVERMAP_UNIQUE", "URBAN", "MAN_MADE" ]
   }
 ]
diff --git a/doc/JSON_FLAGS.md b/doc/JSON_FLAGS.md
index 0c6cd9afcb1bb..c903be0a9858a 100644
--- a/doc/JSON_FLAGS.md
+++ b/doc/JSON_FLAGS.md
@@ -1267,7 +1267,7 @@ See [Character](#character)
 - ```FARM```
 - ```FUNGAL``` Location is related to fungi.  Used to classify location.
 - ```GLOBALLY_UNIQUE``` Location will only occur once per world.  `occurrences` is overridden to define a percent chance (e.g. `"occurrences" : [75, 100]` is 75%).
-- ```UNIQUE``` Location is unique and will only occur once per overmap.  `occurrences` is overridden to define a percent chance (e.g. `"occurrences" : [75, 100]` is 75%).
+- ```OVERMAP_UNIQUE``` Location will only occur once per overmap.  `occurrences` is overridden to define a percent chance (e.g. `"occurrences" : [75, 100]` is 75%).
 - ```LAKE``` Location is placed on a lake and will be ignored for placement if the overmap doesn't contain any lake terrain.
 - ```MAN_MADE``` For location, created by human.  Used by the Innawood mod.
 - ```MI-GO``` Location is related to mi-go.
@@ -1276,6 +1276,10 @@ See [Character](#character)
 - ```URBAN```
 - ```WILDERNESS``` Locations that have no road connection.
 
+#### City buildings
+
+- ```CITY_UNIQUE``` Location will only occur once per city.
+
 ### Overmap terrains
 
 - ```KNOWN_DOWN``` There's a known way down.
diff --git a/src/city.cpp b/src/city.cpp
index 1fa3f21e6010f..fdb4c4298737f 100644
--- a/src/city.cpp
+++ b/src/city.cpp
@@ -101,4 +101,3 @@ int city::get_distance_from( const tripoint_om_omt &p ) const
 {
     return std::max( static_cast<int>( trig_dist( p, tripoint_om_omt{ pos, 0 } ) ) - size, 0 );
 }
-
diff --git a/src/overmap.cpp b/src/overmap.cpp
index a0fe9b06bdb48..6d91e5beeecb0 100644
--- a/src/overmap.cpp
+++ b/src/overmap.cpp
@@ -522,7 +522,7 @@ void overmap_specials::check_consistency()
                                 static_cast< size_t >( 0 ),
     []( size_t sum, const overmap_special & elem ) {
         size_t min_occur = static_cast<size_t>( std::max( elem.get_constraints().occurrences.min, 0 ) );
-        const bool unique = elem.has_flag( "UNIQUE" ) || elem.has_flag( "GLOBALLY_UNIQUE" );
+        const bool unique = elem.has_flag( "OVERMAP_UNIQUE" ) || elem.has_flag( "GLOBALLY_UNIQUE" );
         return sum + ( unique ? 0 : min_occur );
     } );
 
@@ -5627,14 +5627,17 @@ void overmap::place_cities()
             const om_direction::type start_dir = om_direction::random();
             om_direction::type cur_dir = start_dir;
 
+            // Track placed CITY_UNIQUE buildings
+            std::unordered_set<overmap_special_id> placed_unique_buildings;
             do {
-                build_city_street( local_road, tmp.pos, tmp.size, cur_dir, tmp );
+                build_city_street( local_road, tmp.pos, tmp.size, cur_dir, tmp, placed_unique_buildings );
             } while( ( cur_dir = om_direction::turn_right( cur_dir ) ) != start_dir );
         }
     }
 }
 
-overmap_special_id overmap::pick_random_building_to_place( int town_dist, int town_size ) const
+overmap_special_id overmap::pick_random_building_to_place( int town_dist, int town_size,
+        const std::unordered_set<overmap_special_id> &placed_unique_buildings ) const
 {
     const city_settings &city_spec = settings->city_spec;
     int shop_radius = city_spec.shop_radius;
@@ -5665,14 +5668,23 @@ overmap_special_id overmap::pick_random_building_to_place( int town_dist, int to
     };
     auto pick_building = building_type_to_pick();
     overmap_special_id ret;
+    bool existing_unique;
     do {
         ret = pick_building( city_spec );
-    } while( !ret->get_constraints().city_size.contains( town_size ) );
+        // TODO: Add OVERMAP_UNIQUE handling, doesn't seem to be kept track of in an ideal way atm
+        if( ret->has_flag( "CITY_UNIQUE" ) ) {
+            existing_unique = placed_unique_buildings.find( ret ) != placed_unique_buildings.end();
+        } else if( ret->has_flag( "GLOBALLY_UNIQUE" ) ) {
+            existing_unique = overmap_buffer.contains_unique_special( ret );
+        } else {
+            existing_unique = false;
+        }
+    } while( existing_unique || !ret->get_constraints().city_size.contains( town_size ) );
     return ret;
 }
 
-void overmap::place_building( const tripoint_om_omt &p, om_direction::type dir,
-                              const city &town )
+void overmap::place_building( const tripoint_om_omt &p, om_direction::type dir, const city &town,
+                              std::unordered_set<overmap_special_id> &placed_unique_buildings )
 {
     const tripoint_om_omt building_pos = p + om_direction::displace( dir );
     const om_direction::type building_dir = om_direction::opposite( dir );
@@ -5680,17 +5692,21 @@ void overmap::place_building( const tripoint_om_omt &p, om_direction::type dir,
     const int town_dist = ( trig_dist( building_pos.xy(), town.pos ) * 100 ) / std::max( town.size, 1 );
 
     for( size_t retries = 10; retries > 0; --retries ) {
-        const overmap_special_id building_tid = pick_random_building_to_place( town_dist, town.size );
+        const overmap_special_id building_tid = pick_random_building_to_place( town_dist, town.size,
+                                                placed_unique_buildings );
         if( can_place_special( *building_tid, building_pos, building_dir, false ) ) {
             place_special( *building_tid, building_pos, building_dir, town, false, false );
+            if( building_tid->has_flag( "CITY_UNIQUE" ) ) {
+                placed_unique_buildings.emplace( building_tid );
+            }
             break;
         }
     }
 }
 
 void overmap::build_city_street(
-    const overmap_connection &connection, const point_om_omt &p, int cs,
-    om_direction::type dir, const city &town, int block_width )
+    const overmap_connection &connection, const point_om_omt &p, int cs, om_direction::type dir,
+    const city &town, std::unordered_set<overmap_special_id> &placed_unique_buildings, int block_width )
 {
     int c = cs;
     int croad = cs;
@@ -5732,10 +5748,10 @@ void overmap::build_city_street(
             }
 
             build_city_street( connection, iter->pos, left, om_direction::turn_left( dir ),
-                               town, new_width );
+                               town, placed_unique_buildings, new_width );
 
             build_city_street( connection, iter->pos, right, om_direction::turn_right( dir ),
-                               town, new_width );
+                               town, placed_unique_buildings, new_width );
 
             const oter_id &oter = ter( rp );
             // TODO: Get rid of the hardcoded terrain ids.
@@ -5745,10 +5761,10 @@ void overmap::build_city_street(
         }
 
         if( !one_in( BUILDINGCHANCE ) ) {
-            place_building( rp, om_direction::turn_left( dir ), town );
+            place_building( rp, om_direction::turn_left( dir ), town, placed_unique_buildings );
         }
         if( !one_in( BUILDINGCHANCE ) ) {
-            place_building( rp, om_direction::turn_right( dir ), town );
+            place_building( rp, om_direction::turn_right( dir ), town, placed_unique_buildings );
         }
     }
 
@@ -5759,10 +5775,10 @@ void overmap::build_city_street(
     if( cs >= 2 && c == 0 ) {
         const auto &last_node = street_path.nodes.back();
         const om_direction::type rnd_dir = om_direction::turn_random( dir );
-        build_city_street( connection, last_node.pos, cs, rnd_dir, town );
+        build_city_street( connection, last_node.pos, cs, rnd_dir, town, placed_unique_buildings );
         if( one_in( 5 ) ) {
             build_city_street( connection, last_node.pos, cs, om_direction::opposite( rnd_dir ),
-                               town, new_width );
+                               town, placed_unique_buildings, new_width );
         }
     }
 }
@@ -6704,12 +6720,13 @@ std::vector<tripoint_om_omt> overmap::place_special(
     if( !force ) {
         cata_assert( can_place_special( special, p, dir, must_be_unexplored ) );
     }
+
     if( special.has_flag( "GLOBALLY_UNIQUE" ) ) {
         overmap_buffer.add_unique_special( special.id );
-    }
-    if( special.has_flag( "UNIQUE" ) ) {
+    } else if( special.has_flag( "OVERMAP_UNIQUE" ) ) {
         overmap_buffer.log_unique_special( special.id );
     }
+    // CITY_UNIQUE is handled in place_building()
 
     const bool is_safe_zone = special.has_flag( "SAFE_AT_WORLDGEN" );
 
@@ -6881,7 +6898,7 @@ void overmap::place_specials( overmap_special_batch &enabled_specials )
             continue;
         }
 
-        const bool unique = iter->special_details->has_flag( "UNIQUE" );
+        const bool unique = iter->special_details->has_flag( "OVERMAP_UNIQUE" );
         const bool globally_unique = iter->special_details->has_flag( "GLOBALLY_UNIQUE" );
         if( unique || globally_unique ) {
             const overmap_special_id &id = iter->special_details->id;
diff --git a/src/overmap.h b/src/overmap.h
index c2127fed5177d..3ab8fc824c087 100644
--- a/src/overmap.h
+++ b/src/overmap.h
@@ -452,7 +452,8 @@ class overmap
                 const overmap *south, const overmap *west );
 
         // City Building
-        overmap_special_id pick_random_building_to_place( int town_dist, int town_size ) const;
+        overmap_special_id pick_random_building_to_place( int town_dist, int town_size,
+                const std::unordered_set<overmap_special_id> &placed_unique_buildings ) const;
 
         // urbanity and forestosity are biome stats that can be used to trigger changes in biome.
         // NOLINTNEXTLINE(cata-serialize)
@@ -467,10 +468,12 @@ class overmap
         void calculate_forestosity();
 
         void place_cities();
-        void place_building( const tripoint_om_omt &p, om_direction::type dir, const city &town );
+        void place_building( const tripoint_om_omt &p, om_direction::type dir, const city &town,
+                             std::unordered_set<overmap_special_id> &placed_unique_buildings );
 
         void build_city_street( const overmap_connection &connection, const point_om_omt &p, int cs,
-                                om_direction::type dir, const city &town, int block_width = 2 );
+                                om_direction::type dir, const city &town,
+                                std::unordered_set<overmap_special_id> &placed_unique_buildings, int block_width = 2 );
         bool build_lab( const tripoint_om_omt &p, int s, std::vector<point_om_omt> *lab_train_points,
                         const std::string &prefix, int train_odds );
         bool build_slimepit( const tripoint_om_omt &origin, int s );