Advertisement

7th Annual Smithsonian Magazine Photo Contest Natural World
The underground river in Palawan. Carved from limestone, it is the largest cave system navigable by boat.

The underground river in Palawan. Carved from limestone, it is the largest cave system navigable by boat.

Photo Detail
Date Taken: 07.2009
Date Uploaded: 08.2009
Photo Location: Philippines
Camera: Canon EOS DIGITAL REBEL XTi
Copyright: © Kevin Ziechmann