Gary is a hemispherical concrete dome and its foundation encapsulating the entirety of Gary (City-State). Its diameter is about 10 miles.

Substructures

Solar Canopy

The walls and ceiling of the dome are an ArSol solar canopy, simulating a diurnal cycle but without any depiction of a sky, sun, clouds, etc. It simply cycles through different shades of Gary (Color) according to the time of day.

The canopy is equipped with a single speaker in its top-center, which is powerful enough to make announcements throughout the entire city.

Temperature is regulated throughout the city by machinery in the Canopy, obviating the need for cooling, heating or windows in any other structures.

Foundation

The foundation is solid concrete intersticed with several basement levels that house critical infrastructure, a transit system, and a penal colony. There were underground connections to Chicago, but those have been destroyed and filled in. 

Openings

There are very few openings in the canopy. They are used only for crucial functions, like UnGary (Punishment) or access by UnGary (Ambassadorship).