I will be in Kentucky this month (July 2013) and I want to take a tour of Mammoth Cave, preferably the "Historic Tour" or New Entrance Tour". I looked on the park website and it stated there that "If you have a fear of heights or suffer from claustrophobia, this tour [Historic or New Entrance] is not the best choice for you". Now, I am not claustrophobic per se, and small/crowded/tight places don't turn me off but getting down hands and knees and crawling through cave openings just a foot or 2 tall is definitely not for me. So, my question is-how tight is this cave in general, and in particular, the parts of the cave seen on the tours I mentioned above? Do you ever have to squeeze through really tight openings and/or get down on your knees or is it just a bit crowded but nothing to really concern the average guy?