Site of the original Olympic Games in the Alpheus valley of the northwest Peloponnese. It was a major pan-Hellenic sanctuary to the god Zeus, whose festivals came to be dominated by the games. His temple, built in the mid-5th century BC, contains fine sculptures. The games, in which aristocratic athletes from the Greek world competed in a range of events, including athletics, wrestling and chariot racing, were held every four years between 776 BC and AD 393.