Northwest is the mountainous region of north west Vietnam, which shares a border with Laos and China. This area is sometimes known as the North West and is one of three natural geographical sub-regions of northern Vietnam (the other two sub-regions are the Northeast Region and the Red River Delta). Northwest rugged terrain, mountains and more mountains high volume runs northwest - southeast. Hoang Lien Son range to 180 km long, 30 km wide, with a number of high peaks from 2800 to 3000 m. Code River Mountains 500 km long, with heights above 1800 m. Between these mountains are low hills Da River (also known as Da geosyncline). In addition to the great river Black River, Northwest only small rivers and streams including the upstream code. In place for life is a series of limestone plateaus road from Phong Tho and Thanh Hoa, and can be subdivided into the aneurysm Ta plateau, Moc Chau, Na San. Also available as Dien Bien basin, Nghia Lo, Muong Thanh.