Lake, east-central Scotland.
Roughly 3 mi (5 km) in diameter, it is one of the shallowest of the Scottish lochs, having an average depth of 15 ft (4.5 m). It contains a subspecies of brown trout known as Loch Leven trout. Castle Island, one of the lake's seven islands, has the ruins of a 14th-century castle where Mary, Queen of Scots , was imprisoned (1567–68).