One of the clubs in Blackpool claims to have glory holes ... never been there myself yet, because I don't have anyone who would go with me, and a single bloke in a swingers club is often frowned upon .... search for it on the net. Good luck !
Partners in Bury has glory holes, but if you want them in "natural" settings, you'll have no luck in Preston, they've either closed down the bogs or made them all out of metal.