The Oracles were women who, when they made their prophecies, were in a trance-like state and typically made vague, ambiguous statements that were difficult to understand. Fortunately for the people who were there seeking advice on an important decision, there were also high priests who would (for a fee, of course) interpret the meanings of the prophecies. Perhaps what really gave the Oracles their powers (and certainly what gave them their trance-like states) is the fact that under the temple, gasses were rising from the earth which kept the oracles in a somewhat drugged state while they were making their prophecies.
According to Greek mythology, this site was chosen for building a temple for the Oracles because it was the center of the world. How did they know that? The highest Greek god, Zeus, turned loose two eagles to fly free. Wherever the eagles crossed paths was the center of the world. And according to that mythology, when they did, Zeus dropped this stone to mark the spot:
So acccording to Greek mythology, Delhi was the center of the world. I think that in reality, there are two reasons why this spot was chosen for Delphi. First, because of the aforementioned gasses that gave the Oracles their power. But second, because geographically, Delphi is simply an amazing place. It is built on the side of a mountain that rises from the sea to an altitude so high that, on the back side from Delphi, people ski on it. Here are views looking up the mountain, from the theatre that was built above the temple, and looking down to the sea from just below the temple:
Because of its importance to the ancient people of Greece and Rome, many elaborate structures were built at Delphi. Those included some remarkable mosaics in their floors, some of which survive to the present:
There is also a fine museum with many ancient Greek sculptures at the Delphi site. Remember I said they skied on the back side of the mountain above Delphi? When our bus stopped in the nearest town after the Delphi tour, I was somewhat surprised to see that there were multiple ski shops like this one:
This one was even open, although it was still a month or so before the ski season. This town was, in fact, a rather charming little mountain town:
