In the Peak District, a 450 km² outcrop of Carboniferous Limestone is the location of many interresting caves. The area is 40km from north to south and 20km from east to west. The Peak District is a National Park.
The limestone area ist a karst area with typical subterranean drainage. It is surrounded by areas with Triassic Sandstones and Namurian Millstone Grit, which support surface drainage, so there are numerous karst springs along the border of the limestone. Most of the (show)caves are located here, because the springs allow access to the caves.