Blind Descent: the quest to discover the deepest place on earth

by James M. Tabor

Since it's about going down instead of up, this book could sort of be the opposite of Touching the Void, or one of the other books about climbing Mt. Everest. It's pretty well-written, mostly not boring, and manages to convey the excitement and danger of the expeditions even to someone not involved or particularly interested in spelunking. Solid recommendation if you like travel and adventure, extreme sports, survival stories.

My one complaint is sort of a technicality: if the cave starts up the side of a mountain and the bottom of it is at the level of a valley floor, no matter how far it is from top to bottom, it just doesn't feel as "deep" as something below sea level. I've probably just read Journey to the Center of the Earth too many times.