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
Cheddar Gorge gorge are owned by The National Trust. Every year both of the gorge's owners contribute funds towards the clearance of scrub bush and trees from the area. Most of the commercial visitor activity in the gorge is on the Longleat-owned south side, including access to the two main commercial show caves and the visitor centre, which is operated by Longleat-owned company "Cheddar Gorge and Caves Ltd" under director Hugh Cornwell. Due to the fact that tourist numbers have dropped through the show caves from 400,000 a year in the 1980s to 150,000, in 2013 Ceawlin Thynn, Viscount Weymouth who runs