The Tokyo Gantz Room acts as the base of operations for the Tokyo Gantz team and is the location of Gantz for the majority of the series.
There are Gantz spheres located in various places around the world. This is where the recently deceased are brought by the local cyborg inside a Gantz sphere, given weapons and Gantz suits, and then sent out on missions.
The Gantz sphere is in the main room. One side room has two monowheel vehicles and a pile of swords.
The only Gantz rooms shown in the series are the one in Tokyo and one in Kyoto.