highest peak in Tasmania, Australia, rising to 5,305 feet (1,617 m), in the central highlands. At the northern end of the rugged Ducane Range, Mount Ossa, along with several other peaks surpassing 5,000 feet, lies within Cradle Mountain–Lake St. Clair National Park. Its slopes are deeply gouged by glacial corries (cirques). The name, with the adjacent Mounts Pelion and Achilles, is taken from Greek mythology.