The Gladiator Zone is an area on Cybertron, presumably once used for gladiatorial combat. Nowadays the Decepticons live there, and it's in the same sorry state as everything else the Decepticons get their hands on.

Fiction

G.I. Joe vs. the Transformers

Following the defeat of Shockwave, the remaining Decepticons were pushed back to the Gladiator Zone, The Art of War #1 where they started fighting among themselves over pieces of the area. During a battle over territory between the Predacons and Seacons, Serpent O.R. arrived on Cybertron and reunified the Decepticons. The Art of War #2 The Predacons' bunker in the Gladiator Zone was used as the Decepticon headquarters during Serpent O.R.'s rule. The Art of War #3

Notes

• See that graffiti on the wall above the fallen Autobot? Good.