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
Cheddar Gorge gorge are owned by The National Trust. Every year both of the gorge's owners contribute funds towards the clearance of scrub bush and trees from the area. Most of the commercial visitor activity in the gorge is on the Longleat-owned south side, including access to the two main commercial show caves and the visitor centre, which is operated by Longleat-owned company "Cheddar Gorge and Caves Ltd" under director Hugh Cornwell. Due to the fact that tourist numbers have dropped through the show caves from 400,000 a year in the 1980s to 150,000, in 2013 Ceawlin Thynn, Viscount Weymouth who runs