Although the date of foundation of Klaros is not known precisely, it is thought to have been built in 7th century BC or at the beginning of the 6th century on behalf of Apollo, the chief god of Kolophon. The Temple of Apollo in Klaros, located in a flat area in a narrow valley, was very famous in the Hellenistic period and especially in the Roman period because it was operateing as a “prophecy center”. The reason to build the temple on plain land instead of a hill was the presence of a sacred spring and forest.
Throughout its history, Klaros was not constructed as a city, instead it had continuously developed as part of Kolophon. From a square-formed Propylea, which is thought to have been built in the 2nd century AD, there is a street leading to the temple of Apollo; this street is full of columns and statues on both sides. In Propylea, the inscriptions written by those who consulted to the oracle were found. The statue of Apollo at the top of Cella is 7.5 m. high. There is a monumental altar in front of the temple. A new Ionian style temple was unearthed to the north of the temple of Apollo. This temple could belong to Artemis. The artefacts found at the excavations are exhibited in İzmir Archeology Museum.
The sanctuary of Klaros, Kolophon, is located 13 km southeast of Değirmendere and 2 km north of Notion (Ahmetbeyli). The first systematic investigations were initiated by C. Schuchhardt in 1886. Schuchhardt, who performed the localization of the city of Colophon correctly during these studies, later found two tumuli in the valley between Kolophon and the sea; and also identified the location of Notion.
Many inscribed blocks, which were brought from Holy area, were found by Th. Macridy in Notion acropol – (called Kale [Castle] by the people of Ahmetbeyli) and in its immediate vicinity. Discovering these inscriptions in the village, Th. Macridy thougt that the sanctuary could not be far from this region and from the Basilica, and as a result of his research in 1907, he found the upper section of the column, which was mostly worn and stands today in the propylon; and after realizing that it was the Apollo Klarios Sanctuary, he made an excavation and proved the correctness of his thought.
The first scientific excavation in Klaros was made by Th. Macridy and Ch. Picard in 1913. However, when World War I began, excavations were abandoned. The second period of the excavations in Klaros was re-started by Louis Robert with the participation of Jeanne Robert. Having started in 1988, the third period of excavations under the direction of Juliette de La Geniere still continue.