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 in 1989. A collection of fairground art of Wookey Hole was sold in 1997 at Christie's. The present owner is the former circus proprietor Gerry Cottle, who has introduced a circus school. The cave was used for the filming of episodes of the BBC TV series "Doctor Who": the serial "Revenge of the Cybermen" (1975) starring Tom Baker. This has since been referenced in the comedy of "The League of Gentlemen". The cave was also used in the filming of the British series "Blake's 7" (1978) and "Robin of Sherwood" (1983). The caves were used again for "Doctor Who" in