The sanctuary spreads around the splendid green wooded foot of the Kronion hill. Olympia became a centre of worship to Zeus, after whose abode on Mount Olympus the site was named. The valley in ancient times was full of wild olive trees, poplars, oaks, pines and plane trees and it was these that gave the centre the sanctuary the name Altis. The temples and religious buildings were located inside the Altis, the sanctuary to the gods.
Athletic festivals honoring Zeus took place here every four years over a five day period in late summer during a sacred truce observed by all Greek cities. Victors in the games were crowned with a branch of the wild olive tree that stood near the temple of Zeus. This crown bestowed the greatest honor on the athlete, his family and his native city. The sanctuary flourished until 426 BC when Emperor Theodosius II closed all of the ancient pagan sanctuaries.