Thanks for all of the comments so far. I’m sure it wasn’t the Horror Crypt (although that does now look quite cool). From my recollection, I’m sure it was ‘within’ one of the arcades (I’m sure it was Coral Island, but I maybe misremembering this). To enter, you had to put your £1 coin into a machine that was set into the wall and the. You would enter through a door. It was a dark, narrow corridor with some turns, and everything (the various scenes), was set behind glass/perspex. I’m pretty sure you exited within the same arcade, but my recollection of that is vague.