No one who had not first been purified with water was allowed to enter the Abaton for the miraculous cure. On the stelai inscribed with accounts of the god’s miracles, some of these are associated with water, as well as with warm or cold baths, which were said to be crucial for treating certain illnesses. The continuous supply of water was necessary also for serving the needs of the priesthood and the numerous visitors.
The water welled from a spring on Mount Κynortion, from where it was brought to even the remotest point of the Asklepieion, by an excellently organized supply system. The water flowed along an underground aqueduct into a cistern built at the foot of the hill. From there it was brought to the Asklepieion along a stone conduit with numerous branches leading to the many installations: fountains, bathhouse complexes, etc.
Among these was the Bathhouse of Asklepios, an extensive complex contiguous to the Abaton. The traveller Pausanias attributes its construction to the Roman senator Antoninus in the second century AD. It comprised halls of various sizes and many chambers. Some square rooms were pools and the water supply was probably from a built aqueduct.
The complex was constructed on top of an earlier building that also functioned as a bathhouse, most probably serving ritual acts before incubation (enkoimesis) in the Abaton. It was supplied with water from a statue-fountain at the entrance to the Temple of Asklepios, from which a stone conduit channelled water into a settling basin. This hydraulic installation is dated to the fourth or the third century BC.