Underneath Wiltshire is a plethora of places to discover; some more famous than others, variant in scale, condition and uses but no access is as famous as the wonder that is muddy hole!
Browns Folly Mine is an average sized Bath Stone quarry which was originally part of Monkton Farleigh Mine however when the War Department converted part of the quarry in to an ammunitions store they separated part of the quarry which is the area now known as Browns Folly.
http://www.nettleden.com/venues/browns-folly/
http://www.english-nature.org.uk/citation/citation_photo/1002510.pdf
