Copyright 2009 National Geographic

Vietnam isn’t just about the Pho. They can now lay claim to having the world’s largest cave passage. The cave is called Son Doong and it resides in a remote corner of a Vietnamese jungle. The previous record holder was a cave in Borneo that is 1.6 kilometres long. Son Doong’s passage was clocked at 4.5 kilometres by a joint British-Vietnamese expedition before seasonal floodwaters made them turn back. They believe the passage is even longer. The cave boasts stalagmatites over 230 feet high. More on the giant cave at National Geographic.