Delphi was the ancient home of the Oracle of Apollo. It is located just north of the Gulf of Corinth, about a hundred miles northwest of Athens and in the shadow of Mount Parnassus. The ancient complex is perched on the side of a rather steep hill, overlooking the magnificent view over the Gulf and for hundreds of miles in each direction.
The sacred complex at Delphi was not so much built as it coalesced aroung the Hub of the World, marked by a red-rimmed white stone, to symbolise the navel and the umbilical cord. This landmark was eventually included in the various temples that stood on that spot, the latest of which, a Doric temple of Apollo, is the one we can see, partly reconstructed, today.
Leading from a lower point on the mountainside up to the temple is a sacred way, flanked on both sides by small treasuries, built by the city states to house their tributes to the temple. Also along this way stood a magnifisent collection of art and statuary, donated by former supplicants to the oracle, most of which do not survive today. Some excellent examples may still be seen in the adjacent Delphi museum.
Above the temple there is a collection of buildings and open spaces dedicated to learning, physical activities and the arts. The Pythian Games, not unlike the more famous Olympic ones, were held in Delphi every fourth year, for which purpose there is a stadium and theatre there, too.
Some half a mile south of this complex lies the entrance to the gully of the Kastalian Fountain, in which the Pythia bathed before preforming her sacred duties. The topology of this gully is worthy of special notice, since it seems to be located in a narrow crack running along a giant mass of rock. The broken colossus is the size of several 10-story buildings placed side to side and is entirely black and bare of vegetation. This imposing appearance no doubt helped protect the purity of the sacred waters from intruders, for it was said that the two halves of the rock will snap shut on any layman who dared set foot between them.
Just below the entrance to the gully stands the Sanctuary of Athena. Next to it is the famous tholos, or rotunda, a poster-image for delphi even though it was not part of the Pythian complex and cult of Apollo. In fact, there is no theory advanced as to the possible uses of the tholos. However a temple dedicated to a female deity is believed to have been dedicated in this location since very early times.
The modern-day town of Delphi is just a small village of little note, with a few bars and restaurants to accomodate the tourists. It was formerly located quite on top of the archaeological site, and was promptly moved out of the way by the Greek government as a result of the excavation and prservation of the ruins of ancient Delphi.
Sources:
http://www.dilos.com/region/centgr/delphi01.html
And memory.