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
Caves of Meghalaya partially explored, for a total length of caves explored. With an explored length of , Krem Liat Prah in Jaintia Hills is the longest cave in Meghalaya, as well as India, and is listed among the longest caves in the world. Krem Liat Prah contains a huge passage called the "Aircraft Hangar." Since the MAA was established in 1994, the explored caves account for only about 5% of the total underground passages in the state of Meghalaya. Limestone mining for the cement industry is a major threat to the Caves of Meghalaya, causing a major collapse of the Krem Mawmluh