Phong Nha displays an impressive amount of evidence of earth’s history.
According to the assessment of UNESCO, the karst formation of Phong Nha-Ke Bang National Park has evolved since the Palaeozoic (some 400 million years ago) and so is the oldest major karst area in Asia and Phong Nha displays an impressive amount of evidence of earth’s history. It is a site of very great importance for increasing our understanding of the geologic, geomorphic and geo-chronological history of the region.
Phong Nha-Ke Bang National Park is one of the world’s two largest limestone regions. In comparison with 41 other world heritage sites which have karsts, Phong Nha has dissimilar geomorphic, geologic and biotic conditions. The karsts of Phong Nha can be traced back to Palaeozoic era, 400 million years ago. This makes Phong Nha the oldest major karst in Asia. If the Hin Namno, bordering Phong Nha on the west (in Laotian territory) was to be combined with the national park in a continuous reserve, the combined reserve would be the largest surviving karst forest in South-east Asia (317,754 ha).
