Quảng Bình is a province in the North Central Coast of Vietnam. Coordinates 16°55’ to 18°05’ North and 105°37’ to 107°00’ East. It borders Hà Tĩnh Province on the north with the Ngang mountain pass as the natural frontier, borders Quảng Trị Province by the south, borders Laos by the west. The narrowest part from east (seaside) to west (Laotian border) is just 40 km. The provincial topography is characterized by a general slope, higher in the west and lower in the east, with hilly and mountainous areas accounting for 85% of the total area. The Annamite Range is the natural border between Quảng Bình Province and Laos with peaks ranging from 1,000 to 1,500 m, the summit of which is peak Phi Co Pi with the height of 2,017 m. In the east of the province are lower hills and then several narrow plains and river deltas. The seaside sand dunes belt is a natural dam that protects the land from the ocean tides.
Many mount summits concentrate in Phong Nha-Ke Bang area with over 1,000 metres height. Noteworthy peaks are the Peak Co Rilata with ta height of 1,128 m and the Peak Co Preu with a height of 1,213 m.
Mounts in karstic area of the park rise at typical height of above 800 m constitute a continuous range along Laotian-Vietnamese borderline, of which notable summits above 1000 m are: Phu Tạo (1174m), Co Unet (1150m), Phu Canh (1095m), Phu Mun (1078m), Phu Tu En (1078m), Phu On Chinh (1068m), Phu Dung (1064m), Phu Tu Ôc (1053m), Phu Long (1015m), Phu Ôc (1015m), Phu Dong (1002m). Inserting into these summits are 800–1000 m high summits of Phu Sinh (965m), Phu Co Tri (949m), Phu On Boi (933m), Phu Tu (956m), Phu Toan (905m), Phu Phong (902m), núi Ma Ma (835m).
Phong Nha - Ke Bang national park (Vietnamese: Vườn quốc gia Phong Nha-Kẻ Bàng) is a national park and UNESCO World Heritage Site in the Bố Trạch and Minh Hóa districts of central Quang Binh Province. The park borders the Hin Namno Nature Reserve in the province of Khammouan, Laos by the west, 42 km east of South China Sea from its borderline point. Phong Nha-Ke Bang National Park is situated in a limestone zone of 2,000 km2 in Vietnamese territory and borders another limestone zone of 2,000 km2 of Hin Namno in Laotian territory. 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.
Phong Nha-Ke Bang area is noted for its cave and grotto systems as it is composed of 300 caves and grottos with a total length of about 70 km, of which only 20 have been surveyed by Vietnamese and British scientists; 17 of these are in located in the Phong Nha area and three in the Ke Bang area. After April 2009, total length of caves and grottoes are 126 km.Before discovery of Son Doong Cave, Phong Nha held several world cave records, as it has the longest underground river, as well as the largest caverns and passageways.
The park derives it name from Phong Nha cave, the most beautiful of all, containing many fascinating rock formations, and Ke Bang forest.
The plateau on which the park is situated 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 for its geological values as defined in its criteria viii.
In April 2009, the world's largest cave Son Doong Cave, was discovered by a team of British cave explorers of British Caving Association.