The Cradle Mountain-Lake St Clair National Park is part of the Tasmanian Wilderness World Heritage Site. It is a large park with lakes, temperate rainforests and alpine heathland. Cradle Mountain is a jagged dolerite mountain peak. There are sites around the park where the Australian Aborigines lived 10,000 years ago during the last ice age. Tasmania's tallest mountain, Mt. Ossa, 1,617 m (5,305 ft) above sea level, is in the park.
An area of 158,000 acres (63,940 ha) was protected in May 1922 as a scenic reserve, becoming a National Park in 1972. The National Park now covers an area of 397,840 acres (161,000 ha). There is a 73 km (45 mi) walking track, called the Overland Track, between Cradle Mountain and Lake St Clair.