Whether it be from horror films, World War II history, urban myths, there is always something fascinating about the secrets that lie beneath our feet. This is especially so when the alleged undergroundness is beneath a major city.
Despite Governments now selling rights to the ground beneath our feet [or the ground beneath the ground beneath our feet] there is something almost primeval in the need to believe we own where we stand? There can be nothing more frightening in horror movies than the zombie/infected breaking through the floorboards to drag an otherwise vigilant victim down with them to hell. Simply we never expect attack from below? Perhaps this is why in warfare tunnellers have always been despised?
Most intriguing of all are the tales of corridors connecting otherwise disparate places, with entrances to such tunnels through otherwise nondescript facades.