The spa was built in the 3rd century AD and was in operation until the 14th century. Even after a fire in the 6th century, there were no major structural changes.

Next to the Heroon, the Therme is the only building in the town that has survived to some extent. It is located at the foot of the Acropolis and consisted of a palaestra and six other sections.
The quality of the construction and the size of the spa are remarkable for a medium-sized town in a relatively remote place in Lycia.
With a size of 700 square meters, the building is more than twice the size of the central baths of Patara and the southern baths of Xanthos, two of Lycia's largest cities.
The size of the baths was influenced both by the population of a city and by the number of occasional visitors from outside the city. The location of the spa at the crossroads of busy streets suggests that the city was heavily frequented by travellers and the spa was used by them as a welcome rest. Remains of the wall on the opposite side of today's street suggest an aqueduct that supplied the spa with water.