Delphi - Apollo's famous oracle in Greece

19th century speculative illustration of ancient Delphi by French architect Albert Tournaire

Delphi, situated in the South West of continental Greece on the slopes of the Parnassos mountains, was considered by the ancient Greeks to be the center of the world. A huge stone called omphalos (navel of the Earth, picture 3) was regarded as the proof for this claim. In the pre-classical period there might have been a sanctuary of the Earth goddess Gaia, but there is no archeological proof of this myth. To honor the place a large temple was built, dedicated to the Greek god Apollo, whose divine duties included divination, healing, lustration, legislation, incantation, and poetry. The head priestess of the temple, called Pythia, was channeling prophesies, supposedly directly received from Apollo. Nowadays not much is left from the great temple (pictures 5&8), because the whole place closed down in the 4th century CE, when Romans converted to Christianity and started to persecute pagans and their sanctuaries. In the vicinity the ruins of the sanctuary of Athena (picture 1), the theatre (pictures 9, 10), the stadium (picture 11) can be found - all restored by archeologists during various excavations since 1880. Many of the statues that surfaced during the excavations were brought to the nearby museum (pictures 14-18).

Walter Burkert describes the procedure of the oracle in the book “Greek Religion”:
After a bath in the Castalian spring and after the preliminary sacrifice of a goat, she enters the temple, which is fumigated with barley meal and laurel leaves on the ever-burning hestia [Greek for “hearth”], and descends into the adyton, the sunken area at the end of the temple interior. There is where the Omphalos is and where, over a round, well-like opening in the ground, the tripod cauldron is set up.… Seated over the chasm, enveloped by the rising vapours, and shaking a freshly cut bay branch, she falls into a trance.
The ancient Greek people are best known for laying the foundations of logical thinking and mathematics, but their culture included also very mystical aspects.
Socrates says in “Phaedrus” (written by Plato) about the oracle in Delphi:
In reality, the greatest blessings come by way of madness, indeed madness that is heaven-sent. It was when they were mad that the prophetess at Delphi and the priestesses at Dodona achieved so much for which both states and individuals in Greece are thankful; when sane they did little or nothing. As for the Sibyl and others who by the power of inspired prophecy have so often foretold the future to so many, and guided them aright, I need not dwell on what is obvious to everyone. Yet it is in place to appeal to the fact that madness was accounted no shame nor disgrace by the men of old who gave things their names; otherwise they would not have connected that greatest of arts, whereby the future is discerned, with this very word "madness," and named it accordingly.
It is not quite sure what caused the divine madness of the Pythia, but most likely a combination of hallucinogenic gases rising from a hole in the ground and the use of psychotropic substances contained in herbs inspired her prophesies. Her messages were often ambivalent but provided the questioner in many cases with useful guidance.
The fame of the oracle spread all over the Mediterranean world and even emperors came to ask for advice.
The Lydian king Croesus, famous for his wealth, wanted to expand his kingdom further east and therefore made plans to wage a war against the Persian empire, ruled by Cyrus the Great in those days. In order to find out, whether he he would win the war, he asked the Delphic oracle for advice. The answer was that if he attacked the Persians, he would destroy a great empire. Croesus concluded that he would be successful against Cyrus and attacked. It never crossed his mind that he might destroy his own empire. But after losing two battles Croesus was captured. Cyrus ordered him to be burned to death on a pyre. Whether Croesus escaped death or not remains unclear. According to one legend, Croesus told the story of the oracle to Cyrus and the Persian emperor was so touched that he reprieved the Lydian king and made him an advisor to the Achaemenid throne.