The archaeological site of Olympia includes the sanctuary of Zeus and the many buildings erected around it, such as athletic premises used for the preparation and celebration of the Olympic Games, administrative buildings and other lay buildings and monuments. The Altis, the sacred enclosure and core of the sanctuary, with its temples, cult buildings and treasuries, occupies the centre of the site.
It is surrounded by a perivolos, or enclosure wall, which in the late fourth century BC had three gates on its west side and two on the south, and is bordered on the east by the Echo Stoa, which separates the sacred precinct from the stadium. The enclosure wall was extended in Roman times and two monumental entrances were created on its west side.
The stadium of Olympia, situated east of the sacred Altis enclosure, was where the ancient Olympic Games and the Heraia, the women's games in honour of Hera, were held.