Dien Bien is a remote region in Northwestern Vietnam. It is surrounded by Lai Chau and Son La territories of Vietnam toward the east and south, Pu'er City, Yunnan, China, toward the north, and Phongsaly Province in Laos toward the west. Dien Bien is a new territory which was made by partitioning the previous Lai Chau Province in mid-2004, both themselves were once part of the Lan Xang kingdom, at that point changed proprietorship to Vietnam amid the French Colonial time frame. Dien Bien incorporates all the land toward the south of the Da River (Black River), and Lai Chau Province incorporates all the land toward the north of the Da River.