Underwater explorer and photographer Jill Heinerth has dived into unmapped caves deep in the earth, and beneath a giant iceberg. She's seen hidden creatures old as dinosaurs, and witnessed scenes of surreal beauty. Her work is so dangerous, over a hundred of her friends and colleagues have died in caves. She talks about the risks and rewards of her work.
Will Hunt's curiosity took him to the subways of New York City, the catacombs of Paris, underground cities in Turkey, and the inner recesses of caves where ancient societies practiced religious rituals.
We learn about caves from journalist and caver Michael Ray Taylor. His new book is called Caves: Exploring Hidden Realms (National Geographic Society). He has written for the Discovery Channel Online, Audubon, Sports Illustrated, Reader's Digest, and many other magazines. He'll talk about the geology of underwater caves and ice caves, and the secret microbial life flourishing in caves.