Underground water working in cracks and between rock layers has carved out Mammoth Cave's long, horizontal passageways over the past several million years. Mammoth's huge vertical shafts, called pits and domes, have been created by groundwater seeping downward through sinkholes or cracks located beyond the edge of the protective hard layer of sandstone that overlies much of the cave. Water has also been essential in decorating parts of the cave with gypsum formations, stalactites, stalagmites, draperies, and flowstone. To explore Mammoth Cave, you'll want to go on one of the multitude of ranger-guided tours the park offers. There are two main categories of ranger-guided tours.
Underground tours are a great way to learn about the cave's geology and history.
Descend into the cave's deepest reaches to find out how the forces of erosion have conspired over hundreds of millions of years to create Mammoth's massive network of tunnels, chambers, and wondrous rock formations. On the Gothic Lantern Tour , see the cave as nineteenth century cavers saw it and discover the marks of passage they left along the way. These tours range from easy to moderately strenuous. For those who don't mind a few tight squeezes, the park also offers three spelunking adventures . These trips give visitors the chance to experience the true darkness that engulfs a cave when you turn out the lights, yet in which a variety of wildlife manages to survive.