Adventure, yeah. I guess that’s what you call it when everybody comes back alive. – Mercedes Lackey Heading South After leaving my friend Ankit in Hanoi I took a trip south to central Vietnam.  Flying into Dong Hoi, I caught a pre-arranged shuttle to Phong Nha-Kẻ Bàng National Park.   Phong Nha’s claim to fame is its world record worthy cave system.  The largest cave in the world, Hang Son Doong, is here.  The third largest cave in the world, Hang En, is also here.  I came to Phong Nha to camp in Hang En. Let me start by saying I almost didn’t do this particular nature adventure.  Vietnam a cheap country…