May 11, 2012
Ora Cave, Papua New Guinea
Photograph by Stephen Alvarez, National Geographic
This Month in Photo of the Day: Adventure and Exploration Photos
The crash of rapids surrounds expedition leader David Gill, left, and Herb Laeger near the entrance of Ora Cave. Hot acidic waters welling up from deep underground, combined with drainage from heavy rains, have carved a maze of tunnels and chambers through New Britain’s young limestone.
See pictures from the September 2006 feature story "Raging Danger."
Learn more about Papua New Guinea »