National Geographic Assignment

Four men repel down an illuminated cave entrance. Photographed by Stephen Alvarez, an adventure photographer specializing in spelunking.

caving: Four men repel down an illuminated cave entrance. Photographed by Stephen Alvarez, an adventure photographer specializing in spelunking.

All images and information © 2013 National Geographic Assignment • Unauthorized reproduction or use of images is prohibited

For the best experience, please visit the Flash version of this site