The national nature reserves (NNRs) of Scotland are areas of land or water designated under the Wildlife and Countryside Act 1981 as containing habitats and species of national importance. National nature reserves can be owned by public, private, community or voluntary organisations but must be managed to conserve their important habitats and species, as well as providing opportunities for the public to enjoy and engage with nature. There are currently 43 NNRs in Scotland, which cover 154,250 hectares (1,542.5 km2), or less than 1.5% of the land area of Scotland. They range in size from Corrieshalloch Gorge at 7 ha to Mar Lodge Estate, which covers 29,324 ha.

Mar Lodge Estate is a highland estate in western Aberdeenshire, Scotland, which has been owned and managed by the National Trust for Scotland (NTS) since 1995. Its principal building, Mar Lodge, is about 4 miles (6.4 km) west of the village of Braemar. The estate is recognised as one of the most important nature conservation landscapes in the British Isles and occupies nearly 8% of the Cairngorms National Park, covering 29,340 hectares. The natural heritage value of the estate is reflected by the fact that much of it is designated as a Site of Special Scientific Interest (SSSI), a Special Area of Conservation (SAC) and a Special Protection Area (SPA). The entire estate has been classified as a national nature reserve since May 2017, and is designated a Category II protected area by the International Union for Conservation of Nature.