When I was little my parents took me lots of places. We visited many tourist spots and if there were any caverns around we went through them. I remember Ruby Falls in Tennessee. Blanchard Springs Caverns in Arkansas. Carlsbad Cavern in Arizona. And many smaller ones in amongst those larger one. It has been years since then and my memory is not as clear as I would like but they were very interesting. Some of them had bats living in them and other critters. Maybe someday I will go again.