After the Acropolis, Delphi is the most popular archaeological site in Greece. Located 180 kilometres from Athens, a trip to Delphi is listed in just about every tour itinerary and is by far the most popular day trip out of Athens.
In ancient times it was the site of the most important oracle of the god Apollo. Delphi was revered throughout the Greek world as the site of the ομφαλός (omphalos) stone, the centre of the universe, where heaven and earth met.
At the Delphi sanctuary excavations have unearthed settlements that date as far back as the Neolithic era. However evidence of the site's importance dates back to the Mycenaean period (1600-1100 B.C). The functions of the Oracle of Delphi grew over the centuries to include athletic games, cultural events, and Delphic festivals, the most important of which was the Pythian Games, which were held every four years in memory of Apollo's slaying of the Python Dragon. Some of the most prominent edifices on the sacred slopes of Delphi are the temple of Apollo, the ancient theatre, the stadium, the sanctuary of Athena Pronaia with the Tholos, the Kastalia spring, and the various treasuries that adorn the sacred way. The archaeological museum on the site contains many important ancient Greek artefacts from the excavations at Delphi.