Priddy Caves the caves, provide geologists with the means to obtain a better understanding of the geological evolution of southern Britain during the Ice Ages. Priddy Caves Priddy Caves () is an Area: 67.6 hectare (167.0 acre) geological Site of Special Scientific Interest at Priddy in the Mendip Hills, Somerset, notified in 1965. The entrance to St Cuthbert's Swallet is incorporated in the adjacent Priddy Pools SSSI. The Priddy Caves System contains about 16km of surveyed cave passages divided between a number of major and minor networks. All the caves are sink hole systems, fed by sink holes at the ground surface.
Cheddar, Somerset the 2005 television programme "Seven Natural Wonders", Cheddar Gorge was named as the second greatest natural wonder in Britain, surpassed only by the Dan yr Ogof caves. There are several large and unique Sites of Special Scientific Interest (SSSI) around the village. Cheddar Reservoir is a near-circular artificial reservoir operated by Bristol Water. Dating from the 1930s, it has a capacity of 135 million gallons (614,000 cubic metres). The reservoir is supplied with water taken from the Cheddar Yeo, which rises in Gough's Cave in Cheddar Gorge and is a tributary of the River Axe. The inlet grate for the