Downturn is a large sized map. The two main spawns are on either side of the map. There are many streets, but most of the surface is destroyed, caving into the subways below. The underground areas connect to cover much of the map, but can be open to air support in the caved in areas. There are many buildings around the map that can be accessed and climbed on, much of them have broken down walls and much debris on the interior.
The Weapons Armory is in the building south of start, the Equipment Armory is in the building on the northwest side of the map, and the Air Support Armory is in the southwest side at the top of the stairs of the central building.