Looking up to Thorpe Cloud from the road at Thorpe

Thorpe Cloud (left)
The limestone that forms the White Peak was formed about 325 million years ago when it was placed a few degrees south of the Equator and a tropical lagoon. Reefs were mostly formed from corals and they became pure white limestone. Reefs were mostly found in a fringe or barrier around the lagoon. A good example of a barrier reef is the hill behind Castleton on which Peveril Castle was built. There is reef limestone in Middleton Dale and in the Dove Valley, where Thorpe Cloud and Parkhouse Hill stand as isolated reefs