The tour was very good, do-able for all ages as the distance covered isn't massive and although there are some stairs there are also escalators/elevators. Toilets are nearby. Our guide, John, was very informative, spoke clearly and told us about his personal experience of 9/11. The memorial pools were not on due to the high wind, but we returned another day. The museum is huge, very interesting and very emotional. With damaged vehicles, twisted girders and the many personal stories and effects, it really hits home what a devastating tragedy this was for all involved. I found it too hard hitting in parts. We were in there about 1.5 hrs and still missed bits. I've rated the tour as 3 stars only because of the bad experience we had at the beginning of the tour. Due to a mix up with the tour company (not viator) we weren't on the list and, despite being two of the first there, had to wait whilst others were checked in as and when they arrived. I had a ticket which PROVED payment and an email but the rep was having none of it. We were made to feel like gatecrashers. Eventually, he found confirmation, but no apology whatsoever was offered and we missed the beginning of the tour. It was handled very unprofessionally. Also, beware the men selling 'memorial books' - they appear to be connected to the tour but they aren't.