A loch of SE Perth and Kinross Council Area, Loch Leven has a circumference of 10 miles (16 km), an area of 1611 ha (3980 acres) and is the largest lowland loch in Scotland. Located immediately to the east of Kinross, the loch is famed for its brown and rainbow trout fishing, supporting a unique sub-species Salmo levensis which is valued by anglers for its hard-fighting spirit and has subsequently been used to stock waters around the world. Created a national nature reserve in 1964, the loch is a wintering ground for many types of migrating bird and one of Europe's most important wildfowl breeding sites. On the largest island, St. Serf's Island, are the remains of a priory and on Castle Island stand the ruins of Loch Leven Castle in which Mary Queen of Scots was imprisoned for 11 months during 1567-68. The loch was lowered by 1.4m (4½ feet) and reduced to three-quarters of its original size in 1826-36 as part of a major land reclamation and drainage scheme that involved the straightening of the River Leven which drains the loch and enters the Firth of Forth at Leven.
The Loch Leven Heritage Trail was opened in 2008 by Andrew Thin, Chairman of Scottish Natural Heritage, welcoming a group of cyclists who had completed the route around the loch, led by Mark Beaumont (b. 1983). The £1.8-million trail extends to 7¾ miles (12.5 km), taking in the natural history and cultural heritage around the loch.