Cheddar Complex the Pleistocene period. Cheddar Caves contain both active and fossil systems. The active cave system is one of the most heavily studied karst systems in Britain with reference to the conduit and diffuse flow characteristics of its hydrology. Charterhouse Caves include four major swallet caves that provide an indisputable record of Pleistocene landform development in the Mendips and surrounding area. Sun Hole Cave provides a varied fauna radiocarbon-dated to the end of the Late Devensian Cold Stage. Several types of limestone including Clifton Down Limestone, Cheddar Limestone and Cheddar Oolite are visible in the Gorge and surrounding areas with pale
Wookey Hole Caves SSSI designation, which would restrict what farmers and other landowners were allowed to do, would cover the entire catchment area. This was opposed as being too restrictive and difficult to enforce. It was argued that agricultural uses of fields which were not directly in contact with cave entrances would have little detrimental effect on the caves themselves. There was also debate about which caves and cave features should be considered "important". The final settlement resulted in a smaller area being designated and many agricultural practices being removed from the list of proscribed "Potentially Damaging Operations". The entrance weir and sluice