Zoo takes place in 'Bay Area Zoo", located on the San Francisco Bay, with the skyline of San Francisco and the Golden Gate Bridge visible in the distance. Bombsite A is located in an empty African Lion exhibit, while Bombsite B is on the lower level of the HRG Aquarium exhibit.
Originally, fishes were known to spawn outside some of the aquariums, but it was later fixed in a patch.
The fish in the aquarium tanks are the only animals seen throughout the map. Other animals, such as monkeys and tropical birds can be heard in the background but are never actually seen.
The ATMs just inside the zoo's entrance bear logos closely resembling the familiar MasterCard logo. These ATMs are also used in Overpass at bomb site A.
The bomb zones take their designations from the zoo's own location map.
A drink stand just outside the CT spawn can be seen sporting the familiar Popdog logo.
Bus shelters containing the an ad for Mapcore can be seen outside to the left of CT spawn.
Inside the guard's office at the zoo's bay entrance (CT spawn), papers can be seen through the window just above the desk on the wall containing work-in-progress design documents for the map.
The general structure of the map's HRG Aquarium is based on the PPG Aquarium located in Pittsburgh, PA.