Delphi was an important religious site in ancient Greece, home to the most important oracle of Apollo. The oracle was housed in Apollo's temple and was consulted through a priestess called the Pythia before major decisions and events. The site also hosted the Pythian Games every four years. The Temple of Apollo, dating to the 4th century BC, was the major structure and site of worship until its destruction in the 4th century AD under Christianity. Other buildings included treasuries to hold offerings, and the site was overseen by the Amphictyonic Council of Greek tribes.