Wookey Hole Caves then passes through major cave systems such as Swildon's Hole, Eastwater Cavern and St Cuthbert's Swallet, around Priddy, but 95% is water that has percolated directly into the limestone. The southern slopes of the Mendip Hills largely follow the flanks of an anticline, a fold in the rock that is convex upwards and has its oldest beds at its core. On the Mendips the crest of the anticline is truncated by erosion, forming a plateau. The rock strata here dip 10–15 degrees to the southwest. The outer slopes are mainly of Carboniferous Limestone, with Devonian age Old Red Sandstone exposed
Wookey Hole Caves river are used in a handmade paper mill, the oldest extant in Britain, which began operations circa 1610. The low, constant temperature of the caves means that they can be used for maturing Cheddar cheese. The caves are the site of the first cave dives in Britain which were undertaken by Jack Sheppard and Graham Balcombe. Since the 1930s divers have explored the extensive network of chambers developing breathing apparatus and novel techniques in the process. The full extent of the cave system is still unknown with approximately , including 25 chambers, having been explored. Part of the cave system