was the small fountain Tilphossa or Tilphussa, where the seer Tiresias is said to have died. Tilphusium was also the name of a town situated upon the Tilphossium mountain.

The hill bears the form of a letter T, with its foot turned towards the north. From its position between the lake and Leibethrium, there is a narrow pass on either side of the hill. The pass between Tilphossium and the lake was one of great importance in antiquity, as the high road from northern Greece to Thebes