Red River

The Red River, also known as the Hong River or Sông Hồng, is a 1,149-kilometer-long river that flows from Yunnan in Southwest China through northern Vietnam to the Gulf of Tonkin. The river is relatively shallow and carries a lot of reddish silt, giving it a red-brown color. It begins in China's Yunnan province and flows generally southeastward, passing through ethnic minority areas and forming a portion of the international border between China and Vietnam. The river's main tributaries, the Black River and Lô River, join to form the broad Hồng near the city of Việt Trì, and it eventually empties into the Gulf of Tonkin, passing through the Vietnamese capital Hanoi. The Red River Delta is a major agricultural area of Vietnam, with vast areas devoted to rice, and is protected by an elaborate network of dikes and levees.learn more on wikipedia