Caves of the Mendip Hills traverse from one cave to another through the underground rivers led to the development of cave diving; the first cave dive attempt in Britain took place at Swildon's Hole in 1934. The first successful cave dive in Britain was achieved the following year at Wookey Hole Caves, where the last sump is currently the deepest in Britain at . The cave complexes at St. Dunstan's Well Catchment, Thrupe Lane Swallet, Lamb Leer and Priddy Caves have been identified as geological Site of Special Scientific Interest. There are also caves within the Cheddar Complex SSSI. A selection of the better known
Charterhouse, Somerset Charterhouse, Somerset Charterhouse, also known as Charterhouse-on-Mendip, is a hamlet in the Mendip Hills Area of Outstanding Natural Beauty (AONB) in the English county of Somerset. The area between Charterhouse and Cheddar Gorge including Velvet Bottom and Ubley Warren is covered by the Cheddar Complex Site of Special Scientific Interest. The name is believed to come from the Carthusian order of Chartreuse in France, which was established in Witham (near Frome) in 1181 and formed a cell at Charterhouse in 1283 with a grant to mine lead ore. There is evidence, in the form of burials in local caves, of