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
Borra Caves which provide views of the formations. The Araku valley, a hill station about from the Borra Caves, is also a tourist attraction for people visiting the caves. November and December are ideal months to visit the caves. Borra Caves The Borra Caves, also called "Borra Guhalu", are located on the East Coast of India, in the Ananthagiri hills of the Araku Valley (with hill ranges' elevation varying from ) of the Visakhapatnam district in Andhra Pradesh. The caves, one of the largest in the country, at an elevation of about , distinctly exhibit a variety of speleothems ranging in size