Delphi, on the slopes of Mt. Parnassos, was home to the most famous oracle of the ancient Greek world, sacred to Apollo. Ancient Greeks considered it the center of the earth, marked by the sacred stone called the omphalos (“navel”). Pilgrims, generals, and kings from across the Greek world came to consult the Pythia, Apollo’s priestess, before undertaking wars, colonizing ventures, or major decisions. The sanctuary and its surroundings include the Temple of Apollo itself, the Sacred Way lined with treasuries dedicated by Greek city-states, a theater and stadium used for the Pythian Games (one of the four Panhellenic athletic festivals), the Castalian Spring where visitors ritually purified themselves, and the Corycian Cave on the slopes of Mt. Parnassos above the site. Each is covered in more detail on its own page.