Delphi (; Greek: Δελφοί [ðelˈfi]), formerly also called Pytho (Πυθώ), is the ancient sanctuary that grew rich as the seat of Pythia, the oracle who was consulted about important decisions throughout the ancient classical world. The ancient Greeks considered the centre of the world to be in Delphi, marked by the stone monument known as the omphalos (navel).
It occupies a site on the south-western slope of Mount Parnassus, overlooking the coastal plain to the south and the valley of Phocis. It is now an extensive archaeological site with a small modern town of the same name nearby. It is recognised by UNESCO as a World Heritage Site in having had a great influence in the ancient world, as evidenced by the various monuments built there by most of the important ancient Greek city-states, demonstrating their fundamental Hellenic unity.