The designation of protected areas in the UK was made possible by the 1949 National Parks and Access to the Countryside Act. The Act set out how land could be designated as:
National Parks are areas of countryside that include villages and towns, and which are protected because of their beautiful countryside, wildlife and cultural heritage. People live and work in the National Parks and the farms, villages and towns are protected along with the landscape and wildlife. National Parks welcome visitors and provide opportunities for everyone to experience, enjoy and learn about their special qualities. Each National Park is looked after by an organisation called a National Park Authority. There are 15 members in the UK National Park family, covering 21,932 square km on the whole.
Areas of Outstanding Natural Beauty are areas of countryside that include villages and towns. They have the same legal protection for their landscapes as National Parks, but don't have their own authorities for planning control and other services like National Parks do. Instead they are looked after by partnerships between local communities and local authorities. An Area of Outstanding Natural Beauty is exactly what it says it is: a precious landscape whose distinctive character and natural beauty are so outstanding that it is in the nation's interest to safeguard them.
There are 38 AONBs in England and Wales (33 wholly in England, 4 wholly in Wales and 1 which straddles the border) and 8 in Northern Ireland. In Scotland, their equivalent are the 40 National Scenic Areas.
National Nature Reserves represent many of the finest wildlife and geological sites in the country. NNRs were initially established to protect sensitive features and to provide "outdoor laboratories" for research. Their purpose has widened since their early days. As well as managing some of Great Britain's most pristine habitats, rarest species and most significant geology, most Reserves now offer great opportunities to the public as well as schools and specialist audiences to experience the country's natural heritage.
Sites of Special Scientific Interest are the most important sites for the nation's natural heritage. They are highly protected to safeguard the range, quality and variety of habitats, species and geological features, and they are the cornerstones of conservation work, protecting the core of UK's natural heritage.
There is a government agency in each country with the power to designate national protected areas:
Together with the above-mentioned nationally designed protected areas, in the UK there are areas which have been designated internationally by organisations such as UNESCO (for instance the 9 Biosphere Reserves and the 28 World Heritage Sites), as well as numerous Natura 2000 sites: Special Areas of Conservation (SACs) and Special Protection Areas (SPAs).
Sources: National Parks, Countryside Council for Wales, Natural England, Northern Ireland Environment Agency, Scottish Natural Heritage