The dual site of Xanthos and Letoon, located at the mouth of Esen Çayı, the ancient Xanthe River, is the oldest French excavation mission in Turkey.
It is a trilingual inscription that evokes the Xanthians, the Perioeci and locals of Awarna, which helped to find, in the Lycian and Aramaic versions, the old name of that place or an older nearby town.
The city of Awarna also appears in an inscription of Tuthaliya found at Yalburt near Ilgin "KUB XIX 55+". It is associated with Pina, ie Pinata, the Pinara classic of Lycia. So there is no doubt about the designation of this place by Awarna during the second millennium BC.
One may wonder if Awarna is not a distortion of Arinna, a Hittite place, abundantly mentioned, where was worshiped the sun goddess of Arinna. Today, the main sanctuary of this goddess is considered to be near Hattusa. This is, to date, not confirmed by the archaeological research on Xanthos and Letoon.
However, excavations in 1990 in various parts of the ancient town of Xanthos have put a new light on the history of the site before the Greek period and even before the Persian occupation. Several reliefs, found in a very disturbed archaeological context, animal representations reused, a bull and two lions show a close relationship with the Neo-Hittite and Phrygian works of the 9th and 8th century BC. The animals are represented in two opposite directions, such specimens are found in the Hittite palaces.
Regarding the Letoon, the abundance of ruins of the 6th century BC, kept in state, did not permited to examine the existence of previous layers.
My notes of veracity :
The Xanthos site was Awarna under the Hittites: 4/5