We went to a suburban kids museum with Helen's friends and the girls had a great time. They have a word-working section with real hammers, nails and saws (biting nails). Honestly, a kid could saw their finger off. Luckily, it was a small, well-controlled area. They had an employee at the entrance who would ensure children were either old enough or entering with an adult and there was a kid:saw ratio of some sort. Poppy helped Helen and Evie's Mom was helping Carys and of course Carys went for the saw. Well it all worked out in the end without bloodloss and the kids got a little homemade car or in Helen's case, a radio.
They also had a great water play area. I think this is one of the only places I could leave Helen (which of course I would never dare) for an hour or two and come back and she would still be there happily interested and playing as if she just arrived. She LOVES water play.