I went on the free Potter Trail tour as part of the Fringe. Our guide was called Will and he was absolutely fantastic. He was really well informed, able to dispel a lot of myths. He was enthusiastic, which the kids on the tour appreciated in particular. He also had an excellent and quite dry/sarcastic sense of humour though, so it meant his enthusiasm never felt obnoxious. It really was the perfect balance, educational, yet fun for adults and kids alike. I'm so glad we went and I would highly recommend it!