In God of War III, Cronos carries Pandora's Temple across his back.
Pandora's Temple is a massive structure built on the back of Cronos. Kratos travels across the Titan during a major section of the game while seeking the box's power and a way to defeat Zeus.
Cronos had previously been punished by Zeus and condemned to wander through the Desert of Lost Souls. His role connects God of War III to the earlier game, in which Kratos entered Pandora's Temple while it was still attached to the chain of the Titan.
Cronos is distinct from Gaia, who leads the Titans, and Atlas, who appears in other parts of the series. The name is also commonly rendered as Kronos in discussions of Greek mythology.