This site is open to the public.
Blue John is a unique fluorspar cound only in Castleton, Derbyshire whihc makes it the rarest natural formation in Britain. First discovered by the Romans, Blue John vases were found at Pompeii.
Primarily a natural cave with some mine workings, the tour follows the path of a riverbed, the river existing only during the ice ages.
During WWII there were concerns about dangerous chemicals leaking into the environment because of bomb damage.
Of particularn concern was radium and Christies Hospital in Manchester was a leader in research in radiography. It was ruled that any hospital using radium had to take extra precautions, the bulk of their stock had to be kept in holes at least 30 feet deep.
Christies decided that the safest place to store their stock was the Blue John Mine in Derbyashire. The continual leakage of the radium was trapped into glass cells, a special piece of equipment was made so it could be tapped off three times a week. The glasswork was so complicated that a German POW was used to make it. Any radium needed to treat a patient was transported to the hospital under police escort.
In the severe Winter of 1941 there were problems with the electric generator at Castleton so a borehole wqas constructed at the hospital and permission was given to return stocks to the hospital.
Lancashire 1939-1945: The Secret War
Blue John Cavern, WWII, Radium storage and Radon gas