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 (1:50,000 sheet 280, Wells). An example of the rare mineral mendipite was found at the head of the gorge. A stream issuing to the west of the site runs down the tributary valley of Hope Wood before joining the main gorge. The original watercourse which may have cut the gorge into the limestone became diverted underground and now emerges at Wookey Hole Caves to form the River Axe. Various caves within the gorge were inhabited by neolithic people from which flint tools are held in the Wells and Mendip Museum. One particularly fine flint flake can be seen in the