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

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

, between the plains of

Haliartus Haliartus or Haliartos (), also known as Ariartus or Ariartos or 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 Koroneia ( el, Κορώνεια, before 1915: Κουτουμουλάς - ''Koutoumoulas'') is a village and a former municipality in Boeotia, Greece. Since the 2011 local government reform it is part of the municipality Livadeia, of which it is a ...

, maybe regarded as the furthest offshoot of

Mount Helicon Mount Helicon ( grc, Ἑλικών; ell, Ελικώνας) 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. ...

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

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