Phong Nha-Kẻ Bàng is a National Park and a UNESCO World Heritage Site in Quảng Bình Province, in the north of the Central Coast region of Vietnam. The park is 50 km north of Dong Hoi, around 450 km south of Hanoi.
The core zone of this national park covers 857.54 km² and a buffer zone of 1,954 km². The park was created to protect one of the world's two largest karst regions with 300 caves and grottoes and also protects the ecosystem of limestone forest of the Annamite Range region in north central coast of Vietnam.
The plateau on which the park is perched is probably one of the finest and most distinctive examples of a complex karst landform in Southeast Asia. This national park was listed in UNESCO's World Heritage Sites in 2003. In April 2009, the world's largest cave, Son Doong Cave, was discovered by a team of British cave explorers of British Caving Association. Tourist activities in this park includes expedition of caves and grottoes in boats, eco-tourism, discovering the flora and fauna in this park and mountain climbing, trekking.