Tilphossium or Tilphossion ( or Τιλφωσσαῖον), or Tilphusium or Tilphousion (Τιλφούσιον), was a mountain on the southern side of

Lake Copais Lake Copais, also spelled Kopais or Kopaida (; ), was a lake in the centre of Boeotia, Greece, west of Thebes. It was first drained in the Bronze Age, and drained again in the late 19th century. It is now flat dry land and is still known as Kop ...

, between the plains of

Haliartus Haliartus or Haliartos (), also known as Ariartus, Ariartos, Hariartus, or Hariartos (Ἀρίαρτος or Ἁρίαρτος), was a town of ancient Boeotia, and one of the cities of the Boeotian League. It was situated on the southern side of La ...

and Coroneia, maybe regarded as the furthest offshoot of

Mount Helicon Mount Helicon (; ) is a mountain in the region of Thespiai in Boeotia, Greece, celebrated in Greek mythology. With an altitude of , it is located approximately from the north coast of the Gulf of Corinth. Some researchers maintain that Helicon ...

, with which it is connected using Mount Leibethrium. At the foot of the hill was the small fountain Tilphossa or Tilphussa, where the seer

Tiresias In Greek mythology, Tiresias (; ) was a blind prophet of Apollo in Thebes, Greece, Thebes, famous for clairvoyance and for being transformed into a woman for seven years. He was the son of the shepherd Everes (mythology), Everes and the nymph ...

is said to have died. 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 passed through it. This pass was very narrow, and was completely commanded by the fortress Tilphossaeum or Tilphusium, on the summit of the hill.Dem. ''de Fals. Leg.'' pp. 385, 387;

References

Geography of ancient Boeotia Mountains of Greece {{Greece-mountain-stub