Thanks for sharing the cavern/cave. There are some in Davenport we have visited and there are several old mine shafts in our area that are permanently closed. We used to sneak in them all the time as kids. What a great idea that was. The best caves I think I've been in were around the Ozarks and in Kansas. I'd have to search and figure out which ones we went to. Bridal Caves was pretty cool. I always look at the work gone into putting the paths in and I know none of that is an easy task.