The southern castle consists of the remains of the wall of a Phrygian fortification. The site is known, however, because of a chamber excavated underneath with an inscription in Luwian hieroglyphics, which is one of the latest documents from the time of the Hittite Empire.
See:
- John David Hawkins,Hittite Monuments and Their Sanctity, in: Sacred Landscapes of Hittites and Luwians: Proceedings of the International Conference in Honour of Franca Pecchioli Daddi Florence, February 6th-8th 2014, p. 4-6