Natural England has produced National Character Areas profile documents for each of the 159 NCAs in England. NCA 141 Mendip Hills covers most of the AONB with the exception of the Chew Valley and Blagdon Lakes. These are covered by NCA 118 Bristol, Avon Valleys and Ridges (3,858 ha of the AONB). The NCA documents include environmental data and Statements of Environmental Opportunity (SEOs). Much of the Mendip Hills Area of Outstanding Natural Beauty (15,942 ha of its 19,800 ha) lies within the boundary of NCA 141 comprising 53% of the total NCA area (30,300ha).