Caves of the Mendip Hills traverse from one cave to another through the underground rivers led to the development of cave diving; the first cave dive attempt in Britain took place at Swildon's Hole in 1934. The first successful cave dive in Britain was achieved the following year at Wookey Hole Caves, where the last sump is currently the deepest in Britain at . The cave complexes at St. Dunstan's Well Catchment, Thrupe Lane Swallet, Lamb Leer and Priddy Caves have been identified as geological Site of Special Scientific Interest. There are also caves within the Cheddar Complex SSSI. A selection of the better known
Site of Special Scientific Interest (Hong Kong) Site of Special Scientific Interest (Hong Kong) A Site of Special Scientific Interest () or SSSI is a special area to protect wildlife, habitats and geographic features based on scientific interest in Hong Kong. Scientific interests are special features relating to animal life, plant life, geology and/or geography. After being identified by the Agriculture, Fisheries and Conservation Department, these areas are documented by the Planning Department and added to maps. From 1975 to 2005, 67 locations were designated SSSIs throughout Hong Kong. Note: Sites marked with asterisk (*) indicate designation for geological rather than biological interest. Sites marked with #