The Cotswolds were designated as an Area of Outstanding Natural Beauty (AONB) in 1966, with an expansion on 21 December 1990 to 1,990 square kilometres. In 1991, all AONBs were measured again using modern methods. The official area of the Cotswolds AONB was increased to 2,038 square kilometres. In 2000, the government confirmed that AONBs had the same landscape quality and status as National Parks.
The Cotswolds AONB, which is the largest in England and Wales, stretches from the border regions of South Warwickshire and Worcestershire, through West Oxfordshire and Gloucestershire, and takes in parts of Wiltshire, Bath and North East Somerset in the south. Gloucestershire County Council is responsible for sixty-three percent of the AONB.