Hi there. I was on the July 5 trip with Calfan and agree that it was an amazing trip (except the weather we had in parts, but
ABD can't help that). I am also afraid of heights and it did not stop me from any of the activities. When we were in the gondola going up to the ice cave I did not look down too much. There were some staircases in the Ice Cave (staircases freak me out a bit) but they all had handrails (bring gloves) and would not have been too bad if I did not have my clumsy son right behind me bumping into me. The Ice Cave is a big cavern so there is no crawling through it. Some parts of it are as big as an auditorium. The Salt Mine is also a fairly large space. The only part that was a little enclosed was the initial ride into the mine on the train - it just felt like riding on a Disney ride through a tunnel (Calfan has a great picture which includes my kids looking absolutely thrilled to be going in). Absoultely don't let either of these activities scare you off. They are both cool experiences and not too scary even for chickens like me. The hike to the Ice Cave could be too much for some people (we had a two or three older or with health issues) sit it out but most people were fine with it as the walking is broken up into manageable bits.
Any more questions, we would both be happy to help.
Hilary