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
Mendip Hills and subsequent erosion has resulted in a range of surface features including gorges, dry valleys, screes, swallets and others typical of karst landscapes. These are complemented underground by a large number of caves both beneath the plateau and at the base of the southern escarpment. Wookey Hole is one example of the caves of the area. There are also areas of limestone pavement and other karst features. Dissolution of the limestone produced many of the gorges including Cheddar Gorge and Burrington Combe. Springs are a common feature of the eastern part of the hills, a number of which have associated