Water and time have created the fascinating passageways of the world's longest cave system--Mammoth Cave, a World Heritage Site and national park in Kentucky. In addition to the fascinating geology, the story of Mammoth Cave is also a story of incredible creatures that have adapted to life in absolute, eternal darkness; of prehistoric farmers and miners; of more recent miners, entrepreneurs, and promoters; of a doctor's ill-fated medical experiment to treat tuberculosis; of scientists uncovering secrets of the mysterious underworld; and of intrepid explorers extending known frontiers into uncharted underground wilderness. Highly readable text and spectacular underground color photography portray the natural and historic heritage of Mammoth Cave in a large 9 X 12 inch format you will want to display and savor. This book has 48 pages and a laminated paper cover. Forty-seven color illustrations and five line drawings help the reader understand the geological processes at work as well as reveal the mysterious underworld of Mammoth Cave.