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.