In the mid 1980s I was policing out of Slaithwaite. In a quiet moment on Sunday a colleague and I borrowed the key from the Marsden signalman and drove into the closed tunnels to explore.
With the help of a torch, I could see a number of symbols painted in white on the walls of The Cathedral including, in a high position, a pentagram.
Certainly someone had gone to quite some trouble to leave those occult symbols, although that in itself does not prove that the space was actually used for rituals.
Incredible really, half of all crime is violence /sexual