I grew up in Missouri; my dad was amember of the Missouri Speleological Society, and we spent a lot of weekends wandering into unlit holes in the earth. Missou

I grew up in Missouri; my dad was amember of the Missouri Speleological Society, and we spent a lot of weekends wandering into unlit holes in the earth. Missouri, Arkansas and Tennessee are built on limestone and have a lot of subterranean water moving around - meaning there are a lot of caves. Like, a kind of stupid number of caves. When I was a kid, Missouri had more caves than any other state, but it lost the title to Tennessee at some point, as more and more caves were found to be connected to one another. And a few of these caves have been commercialized for a very long time, like the one in the posting. The caves are a pretty magical feature of an otherwise (IMO) pretty bland part of the country.