Caves of the Mendip Hills caves are listed below Caves of the Mendip Hills The caves of the Mendip Hills are formed by the particular geology of the Mendip Hills: large areas of limestone worn away by water makes it a national centre for caving. The hills conceal the largest underground river system in Britain. The hills consist of anticlines of Carboniferous Limestone lying over Devonian Old Red Sandstone, with the sandstone exposed on the summits. When a surface stream running off the sandstone reaches the limestone it sinks below ground through a "swallet", (also known locally as a "slocker"), continuing on its way down
Caves of the Tullybrack and Belmore hills Caves of the Tullybrack and Belmore hills The Caves of the Tullybrack and Belmore hills can be found in south-west County Fermanagh, Northern Ireland. The region is also described as the West Fermanagh Scarplands by environmental agencies and shares many similar karst features with the nearby Marble Arch Caves Global Geopark. The caves are situated under the hills of Tullybrack () – which incorporates Glenkeel () and Knockmore () – and Belmore () and feature three major cave systems: Reyfad–Glenkeel, Noon's Hole–Arch Cave and Boho Caves. They have been described as nationally significant by the Northern Ireland Environment Agency. The