Annamese Range

The Annamite Range stretches for roughly 1,100 kilometres through Laos, Vietnam and a small corner of northeastern Cambodia. Above Thakhek it forms a broad northern section of the chain that separates the Mekong basin from Vietnam’s narrow coastal plain along the South China Sea. The crests lie mostly on the Laotian side. To the west, the ground descends through plateaus toward the Mekong; to the east, it falls sharply toward a dense sequence of short rivers draining into the sea.

The Nape and Mụ Giạ passes cut usable routes through this long mountain barrier. The heights are substantial rather than uniform. Phou Bia reaches 2,819 metres, Phu Xai Lai Leng 2,720 metres and further south Ngọc Linh 2,598 metres. Seasonal forests clothe the slopes and support the saola, douc langur, gaur, Chinese pangolin and, formerly, the Indochinese tiger.

The mountain divide also shaped human geography. Before later resettlement transformed the region, highland communities distinct from the Vietnamese lowland population occupied much of the range and the Central Highlands. Forests and steep valleys therefore linked shelter, exchange routes and separated watersheds. Most crests are on the Laotian side, while Laos and Vietnam each hold basins on both sides of the divide.