Phong Nha – Ke Bang
national park
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. Subject to massive tectonic changes, the
park’s karst landscape is extremely complex with many geomorphic features of
considerable significance. The vast area, extending to the border of the Lao
People’s Democratic Republic, contains spectacular formations including
65 km of caves and underground rivers.