Make a Comment • Email Link • Send Letter to Editor IPFS News Link • Geography Vietnam Hosts Largest Cave 01-19-2011 • arclein By contrast, explorers walked 2.8 miles (4.5 kilometers) into Son Doong, in Phong Nha-Ke Bang National Park, before being blocked by seasonal floodwaters—and they think that the passage is even longer. Watch Streaming Broadcast Live: LRN.fm Watch live shows and archives TV Live Chat Telegram Share this page with your friends on your favorite social network: