Outside the Altis and along the southern surrounding wall of the sanctuary, east of Leonidaion and quite close to the northern side of the South Stoa, lie the Bouleuterion. It was the seat of the high council of the Boule as well as the place where the altar and the statue of Zeus Orkios were. Before the beginning of the games the athletes swore in front of this altar to obey the rules. The building was structured in two phases. During the Archaic period, the two rectangular buildings with the arched west side, the internal colonnades and the ionic collonade in the front were built. In the Classical period, these buildings were connected by a stoa and a square structure in between them.