Founded around the 9th century BC, Caunos became an important Carian city in 400 BC. Right on the border with the Kingdom of Lycia, its culture reflected aspects of both Kingdoms. The tombs, for instance, are in Lycian style. When Maussolos of Halicarnassus was ruler of Caria, his Hellenistic influence reached the Caunians, who eagerly adopted the culture. This mixture of cultures in Caunos may be seen amongst the ruins of its various archaeological remains: the Carian city wall built by Maussolos, the Lycian and Carian tombs, the medieval walls on the acropolis, a Roman fountain dedicated to Vespasianus, a theater from the 2nd century BC, remains of 4 temples, massive Roman baths and a Byzantine basilica of 5th-8th centuries.
One of the most beautiful features of the site are the rock tombs sculpted in the form of the porticoes of small Ionic temples. These are among the most splendid examples of Lycian type funerary architecture in Turkey, although the builders were Carians. The original occupants of the tombs are obscure but are assumed to have been Caunian noblemen and rulers; in most cases they were vacanted and reused in Roman times. The largest one is unfinished, providing a curious glimpse of the method of construction.
The prosperity of Caunos was threatened by the silting of the harbor after which the city was eventually abandoned. The Mediterranean, which once surrounded the hill on which the archaeological site stands, has now retreated 5 kilometers (3 miles) to the south, pushed back by silt from the Dalyan Cayi. The marsh which formed appears to have already been a problem for the harbor activities in the period of Strabo.
The border between the sea and the internal marsh is a long narrow beach called "the Turtleís Beach". This beach is one of the few remaining locations in the Mediterranean sea that has the right conditions for the Giant Loggerhead Turtle (Caretta Caretta) to reproduce. The Giant Loggerhead Turtles have used this beach as a laying ground since time immemorial, especially in June. The females lay their eggs by night in the soft sand, in clutches of about 100. Since the early 90's the beach is closed to the public from 20:00 to 08:00 hours to protect them. The beach is open during the day but swimmers and sunbathers are asked to exercise special care.