The deepest freshwater lake in Australia (190 metres/623 feet), Lake St Clair was scooped during several glaciations over the past two million years.

The Lake forms the southern boundary of Cradle Mountain-Lake St Clair National Park and the finishing point for the Overland Track, one of the worlds best multi-day bushwalks. During summer and autumn (fall), rangers offer a variety of activities such as walks, talks and slide shows for adults and children.

There a number of short walks from the Interpretation Centre around the shores of the Lake at Cynthia Bay (Cynthia Bay is named for the Greek goddess of the moon). Some of the most spectacular walks take three to four hours or overnight such as the walks to Shadow and Forgotten lakes. A pantheon of dolerite mountains Mt Olympus, Mt Orthys, Mt Byron and Mt Ida surround Lake St Clair; at the southern end is a drowned moraine the tumbled rock remains after the glaciations.

The Aboriginal people of the area called the lake Leeawuleena, meaning sleeping water.

Most of Australias mammals are nocturnal but at dusk or dawn around Cynthia Bay you are likely to see two species of wallaby the Bennetts or red-necked wallaby, and the small more timid Tasmanian pademelon. And sometimes wombats and quolls head out after dark; echidnas and platypuses are also common around Cynthia Bay. Birdlife such as black currawongs, strong-billed and black-headed honeyeaters and the yellow wattlebird can be seen and are found only in Tasmania.

Try fishing, boating or the ferry service travelling the 18 kilometre length of the lake, and meet bushwalkers completing the Overland Track.