Metopes from the porches Pausanias 5.10.9 ff.:
Most of the labours of Heracles are represented at Olympia. Above the doors of the temple is carved the hunting of the Arcadian boar, his exploit against Diomedes the Thracian, and that against Geryones at Erytheia; he is also about to receive the burden of Atlas (here Pausanias fails to make reference to the Cerberus labor), and he cleanses the land from dung for the Eleans. Above the doors of the rear chamber he is taking the girdle from the Amazon; and there are the affairs of the deer, of the bull at Cnossus, of the Stymphalian birds, of the hydra, and of the Argive lion.