World's Largest Cave...
Researchers have found in Vietnam what they be... ...explorers walked 2.8 miles (4.5 kilometers) into Son Doong , in Phong Nha-Ke Bang National Park, before being... ...en longer. In addition, for a couple of miles Son Doong reaches more than 460-by-460 feet (140-by-140 met...
https://www.neatorama.com/2009/07/27/worlds-largest-cave/
