According to Greek mythology, Apollo was born on this tiny island in the Cyclades archipelago. Apollo's sanctuary attracted pilgrims from all over Greece and Delos was a prosperous trading port. The island bears traces of the succeeding civilizations in the Aegean world, from the 3rd millennium B.C. to the palaeochristian era. The archaeological site is exceptionally extensive and rich and conveys the image of a great cosmopolitan Mediterranean port.

Delos was the most important Panhellenic sanctuary, and, according to mythology, the birth-place of Apollo and Artemis. The first signs of habitation on the island date from the 3rd millenium B.C., and important remains of the Mycenaean period have been uncovered in the area of the sanctuary. In the 7th century B.C. Delos was already a known Ionic centre because of its religious importance as the birth-place of Apollo.

Athenian influence was initiated on the sanctuary with the first purification of Delos by Peisistratos in 540 B.C. but it gradually developed into a proper domination lasting - with short intervals - until the end of the 4th century B.C., when Delos was finally declared free and independent (314 B.C.).The independence of the island lasted until 166 B.C. when the Romans gave it over to the Athenians.

Delos was a sacred place with splendid buildings and sanctuaries and as such, it was never forgotten; many references are preserved by travellers who visited the island in the last centuries. Numerous pieces of sculpture were transferred to Museums of Greece and abroad, while marbles from the ancient buildings were used as building material by the inhabitants of the nearby islands.

Excavations on Delos started in 1873 by the French School of Archaeology at Athens. Between 1904 and 1914, under the direction of M. Holleaux and thanks to the donation of Duke de Loubat, the most significant sections of the ancient site were uncovered.

Intensive excavations were conducted in the years 1958-1975. The excavations are still carried out by the French School of Archaeology, but the religious, political and commercial centre of the island has already been revealed along with many private houses. Restricted excavations were also conducted by Greek archaeologists at the beginning of the century.

Theatre
The preserved marble theatre was constructed at the beginning of the 3rd century B.C. and replaced an earlier, wooden one. The upper (epitheatron) and the lower part of the theatre, which are separated by the diazoma, are not concentric. The first row of seats, which is for the privileged, is followed by twenty-six stone tiers in the lower part and seventeen more in the epitheatron, divided by eight stairways into seven cunei, that could accommodate about 5.500 spectators. In front of the round orchestra, the remains of the stage-building (skene) are to be seen.

The Temple of Hera
Doric temple constructed in around 500 B.C.; under its cella were revealed the foundations of an earlier temple, dating back to the beginning of the 7th century B.C. In the remains of this earlier temple, a large number of Archaic vases and other votive offerings were found (now exhibited in the museum), many of which bear incised votive inscriptions to Hera. The altar of the goddess was erected to the south of the temple.