If you can get to Wales there's the Big Pit at Blenaevon. We have used it for phobias - the guides are great at cramming the group into the cage, which drops like a stone, they then talk up the presence of rats in the pit, and at some point or other get everyone to turn off their helmet lamps so we are in total darkness. So lots of possible stimuli, and great fun.
While in Wales we also did the Corus Steel Works at Port Talbot. Used to visit there to look at workplace stressors - no longer included in AQA spec except as an option for Paper 3, but a possibility if you are doing the stress option.
Haven't done these trips for a few years now, but as I remember they were both free so the only cost is transport.