14th February 2006, 11:18 AM
Subterranea Britannica have an interest in underground places and it sounds like this would be right up their alley. They also have a database of sites so may be able to give you an indication of its rarity.
http://www.subbrit.org.uk/
They are an incredibly useful and knowledgeable bunch who have answered many of my underground questions over the years.
http://www.subbrit.org.uk/
They are an incredibly useful and knowledgeable bunch who have answered many of my underground questions over the years.