Mendip Hills to the development of cave diving in Britain. The first cave dive was attempted at Swildon's Hole in 1934, and the first successful dive was achieved the following year at Wookey Hole Caves, which has the deepest sump in Britain at 76 m (250 ft). The cave complexes at St. Dunstan's Well Catchment, Lamb Leer, and Priddy Caves have been identified as Sites of Special Scientific Interest. The deepest cave in the Mendip Hills is Charterhouse Cave with a vertical range of . Many caves in the Mendip area were excavated for archaeological and natural history studies by pioneer explorer
Ebbor Gorge by the National Trust, and managed by Natural England as a National Nature Reserve. The land was donated to the National Trust by Mrs G.W. Hodgkinson, in 1967, in memory of Winston Churchill. The site was purchased in 1931 by Wookey Hole Caves Ltd. The site is close to Wookey Hole village and caves and offers views across the Somerset Levels to Glastonbury Tor and beyond. There are three marked trails of varying lengths around the steeply wooded gorge, the longest being long, the shortest of which is suitable for wheelchair users. Because of the ecology of the area was