Phong Nha - Ke Bang National Park: World Natural Heritage

 

Phong Nha - Ke Bang is compared to a giant geological museum of global value because of its complicated geological structure with different types of stone including sandstone, quartz, schist, siliceous limestone, granite, granodiorite and diorite. Phong Nha - Ke Bang has a long, complicated evolution history formed 400 million years before the main geological periods of the earth, experiencing major tectonic structures including faults, folds, and joints that formed high mountain ranges and depressed sedimentary basins. These evolutions also contributed to the diversity of geology, topography and geomorphology of this area. Phong Nha - Ke Bang karsts have global features that provide a lot of information about the earth's development through various periods, from the Late Ordovician - Silurian Age (463.9 - 430 million years ago) to the Quaternary Age (1.75 million years ago). A peculiar geological characteristic of this area is underground rivers and grottos in limestone mountains. Non-limestone landform region is characterised by low mountains covered by flora carpets on the surface. Erosion has created a number of abrasion-accumulation terraces along the valleys of the Son and Chay rivers and at the margins of central limestone massifs. The transition terrain consists of a diversity of rock intercalated by limestone mountains. As situated in a high-rainfall area, rainwater seeped and ran inside limestone mountains. Over tens of millions of years, water has eroded rocks, creating numerous caves in the area. Phong Nha - Ke Bang has 300 caves and grottoes, divided into three main systems, namely Phong Nha grotto system, Vom grotto system and Ruc Mon grotto system.

 

 

The Phong Nha cave system is over 57 km long in total, starting from the south of Ke Bang limestone mountain area. The main entrances are Khe Ry and En caves at an altitude of 300 metres. The grottoes of this tree-branch system run in the northeast-southwest direction. The Vom cave system is over 35 km in length, originating from Ruc Ca Roong Cave at an altitude of 360 metres and ending with Vom Cave. The system runs in south-north direction. Ruc Ca Roong River sometimes hides itself in rock mountains and sometimes appears in narrow and deep valleys before flowing into the Chay River at the entrance of Vom Cave. The Ruc Mon cave system lies in Minh Hoa district where large caves remains not fully explored. Typical caves in Phong Nha - Ke Bang are Phong Nha Cave, Tien Son Cave and Thien Duong Cave, Toi Cavern, En Cavern and Khe Ry Cavern. Especially, Son Doong Cave is considered the largest cave in the world with 200 metres high (some places at 250 metres high), 200 metres wide and at least 8.5 km long. With its topographic, climatic, soil and hydrographical characteristics, Phong Nha - Ke Bang has a rich, diversified and unique flora. Investigations and explorations show that Phong Nha - Ke Bang has a large tropical forest floor, which covers 96.2 percent of the natural area, of which nearly 90 percent is covered by primary forests. The diversity of rare and precious species of animals and plants in Phong Nha - Ke Bang is corollary of its landscape conditions, and is a typical attribute of this forest ecosystem. According to incomplete flora statistics in Phuong Nha - Ke Bang, vascular plants consist of 152 families, 511 branches, and 876 species, including 38 species recorded in Vietnam Red Book, 25 species listed in IUCN Red List of Threatened Species (by the International Union for Conservation of Nature and Natural Resources) and 13 endemic species of Vietnam. A very important discovery in this national park is three rare and precious animals: Saola (also known as Vu Quang ox or Asian biocorn), giant muntjac and Truong Son muntjac are found here. Especially, Saola and giant muntjac are newly discovered species in the world. Among 81 reptile and amphibian species found and recorded, 18 are listed in the Vietnam Red Book and six in the IUCN Red List of Threatened Species. Additional discoveries in the area include 259 butterfly species and 162 fish species, including four endemic ones in Quang Binh and one found for the first time in Vietnam. It also has 302 bird species, including 15 species recorded in the Vietnam Red Book and 19 species recorded in the IUCN Red List of Threatened Species. Specially, imperial pheasant (lophura imperialis), Vietnamese pheasant (lophura edwardsi) and peacocks are globally endangered species. Phong Nha - Ke Bang is considered a giant biological museum in Vietnam.

 

With its clear geological and geomorphologic values, Phong Nha - Ke Bang National Park was recognised as the World Natural Heritage by UNESCO at the 27th Meeting in Paris in July 2003.