A captivating introduction to the world's most fascinating caves, Caves, Revised Edition explores every nook and cranny of these nature-made creations--including lava caves, sea caves, and glacial caves--from Kentucky's Mammoth Cave, to the amazing Paleolithic paintings of Lascaux, to Fingal's Cave of Scotland, which inspired Mendelssohn's Hebrides Overture. Engrossing facts about the geologic origins of these underground voids; their astonishing speleothems, or formations, such as stalactites and stalagmites; and the microscopic extremophile organisms that dwell within are enhanced by exciting photographs and a wealth of other educational resources for further exploration.