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
Cheddar, Somerset and Clifton Down Limestone of the Carboniferous Limestone Series, which contain ooliths and fossil debris on top of Old Red Sandstone, and by Dolomitic Conglomerate of the Keuper. Evidence for Variscan orogeny is seen in the sheared rock and cleaved shales. In many places weathering of these strata has resulted in the formation of immature calcareous soils. Cheddar Gorge, which is located on the edge of the village, is the largest gorge in the United Kingdom. The gorge is the site of the Cheddar Caves, where Cheddar Man was found in 1903. Older remains from the Upper Late Palaeolithic era