Caves of the Mendip Hills then rising up a fracture in the rock. Few caves on the Mendip Hills are more than deep or a few kilometres in length, (with some notable exceptions, such as Swildon's Hole which is over long), but a number are complex with several levels of passages which have been abandoned by the water, for example those around Cheddar. The catchment area of the Cheddar Yeo, which rises in Gough's Cave, measures . Dye marking shows that some of the water travels underground for up to , taking up to 14 days to reach Cheddar. When Banwell Bone Cave was discovered
Caves of the Mendip Hills in 1824, it was found to contain a great many animal bones which have been dated as about 80,000 years old. The earliest scientifically dated human cemetery in Britain was found at Aveline's Hole, in Burrington Combe. The human bone fragments it contained, from about 21 different individuals, are thought to be between roughly 10,200 and 10,400 years old. Archaeological evidence including pottery, flints, hearths, coins, burials and metalwork from the Mesolithic, Neolithic, Bronze Age, Iron Age and Roman eras have been found in many of the caves. A number of Mendip caves were found by miners, for example the