Exmoor was one of the first British National Parks, designated in 1954, under the 1949 National Parks and Access to the Countryside Act. and is named after its main river. It was expanded in 1991 and in 1993 Exmoor was designated as an Environmentally Sensitive Area. The Quantock Hills were designated as an Area of Outstanding Natural Beauty (AONB) in 1956, the first such designation in England under the National Parks and Access to the Countryside Act 1949. The Mendip Hills followed with AONB designation in 1972.