Hang Son Doong (meaning Mountain River Cave) is the worlds largest underground cavern. First discovered in 1991 by a local man, Ho-Khanh, it was more recently surveyed in 2009 by a British team of scientists from the Cave Research Association led by Howard and Deb Limbert. It was only then that its true scale became clear. The cave holds a river and a mini jungle a quarter of a mile below the surface. This is lit by a collapsed doline leaving a hole in the ceiling more than 300ft across. There are even clouds down there.
Hidden in the rugged Phong Nha-Ke Bang National Park in the Annamite Mountains near the border with Laos, the cave is part of a network of 150 or so caves, many still not surveyed.
A friend sent me a powerpoint presentation of slides put together by Edward Longstreet. Amazing but fairly poor quality. National Geographic magazine did a pictorial survey of Hang Son Doong and inevitably their pictures taken by Carsten Peter are stunning. They were featured in the January 2011 issue of National Geographic.
I remember visiting several caves in Halong Bay and impressive though they were this new discovery is in another league. All it needs is a few lanterns down there to complete the picture.
Carsten Peter's shot of a cavern in Hang Son Doong with a view through to the subterranean jungle
