The archaeological site of the Roman Baths is located inside the National Gardens and along Amalias Avenue, in the centre of Athens. The baths were built at the end of the third century AD, but the area was first inhabited in prehistory and was used as a burial ground from the Geometric period. Ancient written sources and recent excavations demonstrate that, although located outside the city walls (before these were extended under Hadrian), this idyllic site with its plentiful running waters and dense vegetation was an important place of worship for many deities. After the completion of the temple of Olympian Zeus and the construction of Hadrian's Gate, during the city's expansion under Hadrian, the area became part of the inner city, and a number of new sanctuaries, private and public buildings, and baths were constructed. The Roman Baths were built after the Heruli incursion of the late third - early fourth century, and were repaired and expanded in the fifth and sixth centuries.
The bathhouse was discovered during excavations for the construction of an airshaft for the Athens Metro. Because the bathhouse covered most of the excavated area and was very well preserved, the airshaft was moved further south so that the finds could be preserved in their original location. The bathhouse was conserved, roofed, and made accessible to the public in 2003-2004.