A Hidden Gem in the Vietnamese Jungle
Only a few years ago, hidden in the Vietnamese jungle a British caver found breathtaking cave passages. These cave passages are hidden within The Phong Nha-Ke Bang National Park. They are about 2.5 miles long and over 900 ft high, so large that not even these pictures below can justify how large they are. They are now known as the world’s biggest cave passages in the world. Over 150 of these caves carry hidden passageways of waterfalls and are looked upon as the most unique and unusual.
Source: http://www.dailymail.co.uk/sciencetech/article-2019775/Inside-worlds-biggest-cave–large-end-found.html