This is my son crawling the "wild tour" of Cumberland Caverns, TN last year at age 12. [His Scoutmaster took the photo.]
I was bravely holding down a picnic table in the commons area of the caverns at the time. I know my limits. One of the dads that did the crawl admitted afterwards that he started to panic a little, but kept it under control.
On one of these tours, you cain't turn around and go back. It ain't like an outdoor hike where you can turn around and go back after 1/2 mile if you decide you ain't up for it. Or if your knee is getting gimpy.
So to all those that can do this, more power to you. Maybe because Cumberland was drier than Raccoon Mt., there was less slipping and banging of knees. My son said he preferred this dry "wild tour" of Cumberland Caverns to the muddier, more slippery Raccoon Mountain Caverns tour.
I guess I should have taken some crawling photos in Raccoon Mt., but when I am doing that and pushing a duffel bag, I am thinking "I want out", not "Gee, this is a Kodak moment".