Didyma was a cult center for the city of Miletos. It is located in the present-day village of Yenikoy, about fifteen kilometers from the site of Miletos. In ancient times, it was connected to its mother city by a sacred road that had statues located on either side of it.

The Didymaion-the temple to Apollo and its oracle at Didyma-was of considerable repute among the ancients. German archaeologists excavating at the site have shown that the earliest sanctuary here was built in the 8th century B.C. and that it was enlarged into an enormous temple around 560 B.C. After their bloody suppression of the lonian rebellion, the Persians sacked and laid waste to Miletos (which they regarded as the instigator) and the Didymaion in 494 B.C. It was during this assault that the temple's cult statue of Apollo was carried off to Ecbatana. After Alexander the Great defeated the Persians in 334 B.C., the lonian cities regained their independence and work was begun on reconstructing the Apollo temple. Around 300 B.C., King Seleukos I of Syria, who then controlled western Anatolia, had the bronze statue of Apollo brought back from Ecbatana to be installed in the new temple, to whose construction he also provided monetary assistance. The new building was designed by the architects Paionios and Daphnis. The former was from Ephesos and was one of those who worked on the Artemision there.

The temple was planned on a much grander scale than the original sanctuary and indeed it was the third largest religious structure in the ancient world being surpassed only by the Ephesian Artemision and a temple on this island of Samos. The Hellenistic temple measured 109.34 by 51.13 meters and had a total of 124 columns.

It was set on a seven-stepped platform measuring 3.5 meters high and in the center of the east front there was a separate flight of fourteen steps.

The construction of so huge a building naturally took a long time and continued during the 3rd and 2nd centuries B.C. One section was only completed in Roman times. While the temple suffered repeatedly from fires and earthquakes, it sustained the worst damage in an earthquake in 1493.

The columns still standing measure 2.40 meters in diameter and 19.70 meters in height. The double row of columns surrounding the temple was covered over with a marble roof as was the temple proper. The central courtyard measured 53.63 by 21.71 meters and was the site of the Archaic-period temple. During Hellenistic times, a small temple (called a naiskos) was built here to house the bronze statue of Apollo. Its surrounding walls were 25 meters in height and decorated with gryphons. The cella was unroofed. East of the adyton (sacred courtyard) is a great stairway of twenty-four steps measuring 15.20 meters wide. This flight of steps leads up to a windowless, three-doored hall where the oracle was written down and delivered. The hall measured 20 meters high and had a marble roof. East of the chamber, a door 5.63 meters wide and 14 meters high leads to the pronaos. The pronouncement of the oracles could only be listened to from outside the chamber. Stairways led to the upper floor. On either side of the entrance are doors measuring 2.25 meters high and 1.2 meters wide that each connects to a narrow, vaulted tunnel leading to the adyton. At the far end of each corridor is a small propylon-like room.

After viewing what is unquestionably one of the most impressive temples of the ancient world, with take our leave with amazement.