As of version 0.31.25 (at least), the only time ruins will appear on the map is when a Dwarf fortress mode fortress is abandoned. These abandoned fortresses will appear as
μ on the fast travel map in Adventure mode and may be reclaimed using Reclaim fortress mode.
See the Map legend for more information on map symbols.
|World Generation (Basic/Advanced) - Regions - Climate - Surroundings - Map legend|
|Civilizations - Sites ( Cave - Town - Fortress - Ruin ) - Calendar|
|Aquifer - Brook - Island - Tunnel - Volcano - Waterfall|
|Biomes|| Chasm/Caverns - Desert - Forest - Glacier - Grassland - Lake - Mountain|
Murky pool - Ocean - River - Savanna - Shrubland - Tundra - Wetland