Phong Nha-Ke Bang
Da Wikipedia.
Phong Nha-Ke Bang is a national park in Pruvincia 'e Quảng Bình, Vietnam. The park has over 300 caves and grottoes with total length of 126 km. The park also has biodiversity. In July 2003, UNESCO included this park in its world heritage sites. In April 2009, British explorers discovered a new cave here, they declared it the largest cave in the world.[1]
