Phong Nha-Ke Bang
Phong Nha-Ke Bang es national park in Quang Binh provinco, Vietnam, 50 km norda de Dong Hoi, 44 km norda Dong Hoi aeroportuo, suda Hanoi. In 2003, UNESCO included this park in its world heritage sites. The park has 300 caves and grottoes with total lenth of 70 km. It also has biodiversity.  In April 2009, British explorers discovered the world’s largest cave here.