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
Cave Diving Group Neath River Cave. Progress and development of equipment and techniques have always come in phases, and with this progress, although still hoping to discover dry caves, came diving of a purely exploratory nature. This has led to advances at Wookey Hole and Cheddar Gorge caves in Somerset. In Derbyshire a great deal of effort has produced significant discoveries in the Peak Cavern/Speedwell Cavern system. In South Wales many kilometres of Daren Cilau were first trodden by cave divers; and the link with Elm Hole and Pwll y Cwm was another major feat. In the north of England, divers have made