Kentucky's Mammoth Cave is one of the world's most famous and remarkable caves. Huge open spaces and intricate rock sculptures are hidden beneath the surface of the Earth in this system of caves and caverns. A result of karst topography, Mammoth Cave has to be seen to be believed. As you can see from the image on this page, Mammoth Cave is open for tours. There is even an underground river you can travel down by boat! Please view the video clip Karst Topography and Mammoth Cave from eMediaVA℠, to learn more about this cave system and its formation.