Overpass is the Counter-Strike map identified by the filename de_overpass.
The “de” prefix means the map belongs to the bomb-defusal format, while “overpass” is the map’s internal and public name. Overpass was created for Counter-Strike: Global Offensive and is set in a European urban environment featuring an overpass, a canal, parks, and underground routes.
Its layout is unusual within the series because the bombsites are connected by a mixture of open outdoor areas and enclosed underground spaces. This creates long sightlines in some sections and fast rotations through tunnels and stairways in others.
The filename can be confused with the names of other defusal maps, such as de_cache or de_train. Those names identify different locations and layouts. In map files, “de_overpass” specifically refers to Overpass, not to a generic map category or a community nickname.