Over the summer, we visited Mammoth Cave, in Kentucky.
Mammoth Cave, as it's name suggests is giant. It is with world's largest cave system by far, and they are still discovering other branches and making new maps to record recent discoveries.
An interesting thing about the place is that it has been open for tours since the 1840's. Hard to imagine. Wealthy North Easterners traveled by stage coach for months to visit the place. There was a small retreat type hotel, but the draw was the cave.
The property above ground at the time was owned privately, and the property owners would have their slaves give tours. Some of the slaves became known for their excellent tours and knowledge of the cave and it's many underground passageways.Some of these slaves earned enough money in tips to buy their freedom.