Cave

In 2009, a local farmer brought a group of British explorers to the entrance of a cave he had found years earlier in Vietnam s Phong Nha Ke Bang National Park. They were excited at the prospect of finding a new cave system, but what they found was an underground river running along the floor of the single largest cave passage that has yet been found.Take another look at the above image; in case you missed it, there s a caver standing on the rock near the middle of the frame. Note that you cannot see the cavern s ceiling above him. The cave is in a very remote region previous cave seeking expeditions to the area likely came very close to finding it, but the terrain is exceedingly difficult. At least five kilometers (three miles) long, the cavern boasts natural skylights (where weaker limestone has washed away) and spectacular ceilings nearly 300 meters (1,000 ft) high.