a wooded mountain in Thessaly in the district of Magnesia, between Volo and the east coast. Its highest point (mod. Plessidi) is 5340 ft. It is famous in Greek mythology; the giants are said to have piled it on Ossa in order to scale Olympus, the abode of the gods; it was the home of the centaurs, especially of Chiron, who had a cave near its summit, and educated many youthful heroes; the ship "Argo" was built from its pine-woods. On its summit was an altar of Zeus Actaeus, in whose honour an annual festival was held in the dog-days, and worshippers clad themselves in skins.