Mendip Hills
This Natural Area is underlain by limestone and supports characteristically species-rich grasslands and woodlands on thin soils. The geology of the area is important and contains fossil-rich exposures, stratigraphic sites and karst (limestone) features such as caves and a spectacular limestone gorge. Three large reservoirs in the area are important for their populations of wintering wildfowl. Caves and mines provide winter roosts for bats and the dormouse has one of its strongest British populations in the woods and hedgerows of the Mendip Hills.

Somerset Levels and Moors
The Somerset Levels and Moors is the largest area of lowland wet grassland and associated wetland habitat remaining in Britain, covering about 35,000 hectares in the floodplains of the Rivers Axe, Brue, Parrett, Tone and their tributaries. The majority of the area is only a few metres above mean sea level and drains via a large network of ditches, rhynes and rivers.

The Levels are mainly used for summer cattle grazing, often in conjunction with hay or silage production, although withy (willow) growing is also an important traditional activity. The Somerset Levels and Moors supports internationally important numbers of waterfowl in winter. Breeding birds includes significant populations of waders associated with lowland wet grassland and the Natural Area is regarded as one of the best areas for breeding waders in lowland Britain.