July 24, 2009--Cavers' headlamps light up the towering walls of Vietnam's Son Doong cave, the largest single cave passage yet found. First explored earlier this year by a joint British-Vietnamese team, the cave measures at least 262-by-262 feet (80-by-80 meters) in most places and is at least 2.8 miles (4.5 kilometers) long.

"For a couple of kilometers it is more than 140 meters [460 feet] wide and 140 meters [460 feet] high," said Adam Spillane, a member of the British Cave Research Association expedition that explored the massive cavern.

Son Doong beats out the previous world record holder, Deer Cave in the Malaysian section of the island of Borneo, conceded Andy Eavis, president of the International Union of Speleology and discoverer of the now demoted Deer Cave.