Until now, the Capito Baths in Miletus, built during the reign of Emperor Claudius (41-54 AD), were considered the oldest known Roman bathing complex in Asia Minor. This summer, however, in addition to the previously unearthed Imperial Baths(ca. 120-165 AD — with a surface area of more than 5,000 square metres), a second bathing complex was discovered in Sagalassos, below the remains of the Imperial Baths. It is much older and smaller than the Imperial Baths and is dated to 10-30 AD, though it was probably built somewhat earlier, during the reign of Augustus or Tiberius. The complex measures 32.5 by 40 metres and is far better preserved than was originally thought. The walls must have been at least 12 metres high, of which 8.5 metres remain erect today.
These Old Baths were replaced by the larger Imperial Baths,when Hadrian selected Sagalassos as the centre of the Imperial cult for all of Pisidia, to which the city belonged. This included the organisation of festivals and games (agones), which attracted thousands, so that a new urban infrastructure became necessary in order to accommodate the Pisidian visitors to these events.