The warm metallic Soulas spring is situated on a hill, to the south of the Asclepeion, behind the holy grove. It is somewhat hidden, next to the Zeioula river, between the sixth and seventh watermill.
The water from the source runs under a gigantic rock and a built structure, resembling a cistern, located just next to it, is full of tepid water that is warm enough (22,4 to 23 degrees celsius) to bathe in even in the dead of winter. Something for the brave to consider….If you visit the source during spring, you will be fortunate enough to see beautiful lilies blooming.
This hot source contains solid and gas components in small quantities and is classified as “akratothermen”. The water comes out from two exits, one cold and the other tepid, whilst the radioactivity level is very low (0,85 Mache units).
Like all ancient natural hot springs and sources of the area, the water was used by Hippocrates at the Asclepeion for healing purposes, as witnessed by the remains of an aqueduct system that can be found on the third terrace of the archaeological site. In recent times, the Soulas spring was still used for balneotherapy by the Koans who would go to the source for a daily excursion.
The Soulas spring is also known as the source of Ai Soula, Soulou, Agiou Sila. Its name probably comes from the very big rock that lies next to it (“solos” meaning metal bulk). The name Ai Soulas seems to be more recent and may be linked to the presence, in the vicinity, of a small church dedicated to Saint Silas, whose location is nowadays unknown. Some signs of a structure can be seen on the big rock, while higher up to the south, remains of a small ancient temple are still visible. Some also call it the “spring of Ai Soulas”, which may derive from the Turkish word “sulu” meaning watery, just like the Soulou river that runs next to the source.