to Sphairos (Pelops's charioteer) and Poseidon and was possessed by the sea god in the night. The mix gave Theseus a combination of divine as well as mortal characteristics in his nature; such double paternity, with one immortal and one mortal, was a familiar feature of other Greek heroes. After Aethra became pregnant, Aegeus decided to return to Athens. Before leaving, however, he buried his sandals and sword under a huge rock and told Aethra that when their son grew up, he should move the rock, if he were heroic enough, and take the tokens for himself as evidence of his royal parentage. In Athens, Aegeus was joined by Medea, who had left Corinth after slaughtering the children she had borne to Jason, and had taken Aegeus as her new consort. Thus Theseus was raised in his mother's land. When Theseus grew up to be a young man, he moved the rock and recovered his father's tokens. His mother then told him the truth about his father's identity and that he must take the sword and sandals back to the king Aegeus to claim his birthright. To journey to Athens, Theseus could choose to go by sea (which was the safe way) or by land, following a dangerous path around the Saronic Gulf, where he would encounter a string of six entrances to the Underworld, each guarded by a chthonic enemy. Young, brave, and ambitious, Theseus decided to go alone by the land route and defeated many bandits along the way. The Six Labours The six entrances to the underworld, more commonly known as the Six Labours, are as follows: At the first site, which was Epidaurus, sacred to Apollo and the healer Asclepius, Theseus turned the tables on the chthonic bandit, Periphetes, the Club Bearer, who beat his opponents into the Earth, taking from him the stout staff that often identifies Theseus in vase-paintings. At the Isthmian entrance to the Underworld was a robber named Sinis, often called "Pityokamptes" (). He would capture travelers, tie them between two pine trees that were bent down to the ground, and then let the trees go, tearing his victims apart. Theseus slew him by his own method. He then seduced Sinis's daughter, Perigune, fathering the child Melanippus. In another deed north of the Isthmus, at a place called Crommyon, he killed an enormous pig, the Crommyonian Sow, bred by an old crone