Delphi stands on a steep slope of Mount Parnassus, in Central Greece, looking down a valley of olive trees towards the Gulf of Corinth. For a thousand years it was the most important religious site in the Greek world, and Greeks believed it was the centre of the earth.

The story explains the claim. Zeus released two eagles from opposite ends of the world and let them fly towards each other. They met here. The spot was marked with a stone called the omphalos — the navel.

The oracle

Apollo took the sanctuary by killing Python, the serpent that guarded it. From then on the god spoke here through a priestess, the Pythia.

The process was strict. Before speaking she washed and drank at the Castalian Spring, then went down into the innermost room of the temple, sat on a bronze tripod and chewed laurel leaves. Those who came to ask had to purify themselves at the same spring, offer a cake and an animal, submit their question to the priests in advance, and draw lots for the order in which they would be heard. They stood where they could not see her.

At first the oracle spoke only once a year, on Apollo's birthday. Later it was one day a month, and not in winter, when the god was believed to be elsewhere. That is nine days in a year — and kings, cities and generals across the Mediterranean planned around them. At the busiest periods three women served as Pythia to keep up.

The answers were famously open to more than one reading. The most quoted example is the reply given to Croesus of Lydia, who was told that if he attacked Persia he would destroy a great empire. He attacked. The empire he destroyed was his own.

Wealth and war

Cities that received good answers sent gifts. They built small marble buildings along the road up to the temple, called treasuries, to hold them, and filled the sanctuary with hundreds of bronze and marble statues. Delphi became extraordinarily rich.

That wealth was fought over. Four Sacred Wars were declared over control of the sanctuary between the sixth and fourth centuries BC. The Amphictyonic League, an association of Greek peoples, managed it, and the Pythian Games were held here every four years — the second most important games after Olympia, and the only ones with musical as well as athletic contests.

The last recorded prophecy was given around AD 393, when the emperor Theodosius ordered all pagan sanctuaries closed.

The village on top

By the Middle Ages a village called Kastri stood on the sanctuary, its houses built out of the ancient stone. Everyone knew what lay underneath, but nobody could excavate a living settlement.

It took an earthquake in 1870 and a determined Greek government to change that. The whole village was bought out and moved to where modern Delphi now stands, and in 1892 the French Archaeological School began what became known as the Great Excavation. They laid a small railway across the site to carry away the spoil. Within a year they had uncovered the Treasury of the Athenians.

What to see today

The Sacred Way climbs in a zigzag from the entrance. It is lined with the bases of monuments and the remains of the treasuries, of which the Treasury of the Athenians has been rebuilt and stands complete.

Above it is the Temple of Apollo, with six columns re-erected. The famous maxims — Know thyself, Nothing in excess — were carved at its entrance.

Higher still is the theatre, and above that a steep path leads to the stadium, where the Pythian Games were run. It is the best preserved in Greece and most visitors do not make the climb. It is worth it.

Below the main site, on the other side of the road, is the separate Sanctuary of Athena Pronaia, with the Tholos — a circular building of the fourth century BC, three of whose columns still stand. Nobody knows what it was for. Between the two sites, beside the road, is the Castalian Spring.

The Archaeological Museum is at the entrance. Its best-known object is the Charioteer of Delphi, also called Heniokhos, the rein-holder.

It is a life-size bronze of about 470 BC, and one of only about five large Greek bronzes that survive from the classical period. It was dedicated by Polyzalus, the ruler of Gela in Sicily, after his chariot team won at the Pythian Games, and it originally stood in a group with a chariot, four horses and two grooms. Only the driver came through complete, apart from his left arm.

It survived because it was buried. The earth protected the metal, and the statue still has its inlaid glass eyes.

The museum also holds the Sphinx of the Naxians, the twin archaic statues of Kleobis and Biton, and the omphalos stone.