#17. Cave Spring
Cave Spring is an excellent example of karst systems. The spring empties 32 million gallons of water a day into the Current River. A few miles from the spring is Devil's Well, a massive underground lake that is visible via a small but deep sinkhole in the top. It can be visited and viewed from the top. The water makes it's way down to the river and exits through the portal of the cave. The cave doesn't go back very far but it's still a popular stop of a float down the Current River.