The Temple of Apollo at Claros (also called Klaros) was a very important center of prophecy as in Delphi and Didyma.
The temple, which probably replaced an earlier one, is dated to the third century BC and is the only temple built in Doric style in Ionia. It was built upon a stepped platform measuring 26 by 46 meters and had a unique plan with two adytons beneath the cella. The front adyton was used as a waiting room for the priest and scribes. Prophecy was performed in the backward adyton where the sacred spring was located. Only the oracle was permitted to enter this area.
In the naos of the temple, the base of a statue of Octavianus (Augustus) dating to 31-28 BC was discovered. Emperor Tiberius was also honoured in the temple.
Emperor Hadrian made a considerable contribution to the reconstruction of the temple in the 2nd century AD. The architrave and the tympanum of the temple were completed under his sponsorship.
Claros was located on the territory of Colophon, one of the twelve Ionic cities, twelve kilometers to the north. The coastal city Notion lay two kilometers to the south. The ruins of the sanctuary are now found north of the modern town Ahmetbeyli in the Menderes district of Izmir Province and thirteen kilometers south of Ephesus.