Didyma became a sacred place in the 8th century B.C. There were two important temples here—the Apollo and Artemis temples. During the Archaic and Hellenistic periods, the temple of Apollo was a prime sacred site for Anatolians. It was destroyed by the Persians in 494 B.C. and the cult of Apollo was taken to Persia.

The temple at Didyma was reconstructed and the cult statue was brought under the leadership of Diaddochen Selekus. He began a new temple in place of the old one in 300 B.C. The structure was never completed. The temple was 109m long and 51m wide and had 124 ionic columns. The pronaos had 12 columns over a base structure of seven steps all around. The Adyton (cella) was reached via an arched tunnel. The cella was open. At the centre of the courtyard, was the temple—Naiskos. This little building was the sacred place where the cult statue of Apollo stood.

Some of the temple stones are carved with letters that identify the workers’ daily wages. The temple was richly ornamented—column bases, fallen pieces of the Medusa frieze from the entablature, fragments of the gryphon frieze within the cella, can all still be seen. The ceilings of the covered stairways have a fret pattern; referred to as the labyrinth, they emphasize the Minoan origins of the oracle.

According to legend, all suppliants to the temple would assemble in front of the building and purify themselves with water from the sacred well. They were obliged to pay a tax proportionate to the seriousness of their request. For a private affair, suppliants were charged 11 times the standard tax. The next step was to sacrifice an animal—usually a goat—in order to learn whether the god was willing to receive a suppliant’s request.

Before the sacrifice, cold water was thrown over the animal. If it showed no reaction, the process had to be repeated. The suppliant then entered the naos, addressed his questions to the priest, and then was taken to the pronaos. The sacrificed animal organs—especially the liver—were carefully examined. Then the priests gave the suppliant’s questions to the priestess, who would drink water from the sacred well and begin uttering meaningless words and sounds, which were interpreted by the priests. The oracle’s meaning was then written in understandable language in the chresmographeion or oracle office. All the words uttered by the priestess were communicated to the suppliant by a priest.

Along the southwest side of the temple was a stadium; the steps of the temple were used as seats. A quadrennial festival and games took place here, shared by the city of Miletus.