Phong Nha - Ke Bang National Park is a UNESCO World Heritage Site, located in the Bo Trach and Minh Hoa Districts of central Quang Binh province , in north central Viet Nam . Phong Nha-Ke Bang is famous for its cave systems . It has 300 caves with a total length of about 70 km , of which only 20 have been surveyed by Vietnamese and British scientists . The park contains many fascinating rock formations and Ke Bang forest . Travelers should take a boat ride through underground rivers to experience nature and enjoy fresh air 1. Is Phong Nha-Ke Bang famous for its cave systems ? 2. how many caves are there in Phong Nha-Ke Bang ? 3. What should travelers do when they travel there