A small, family owned business, it was discovered in 1862 by an Ozarks farmer — or more precisely, by his dog, who crawled through an entrance. It wasn’t until five years later that the first exploration took place: 12 women from Springfield, Missouri, answering a newspaper ad seeking explorers, ventured into the cave. Their names remain on a cave wall today. The cave is the only ride-through cave in the United States and toured by jeep-drawn trams.