Red River also
known as Hong Red, Song Cai, Song Ca- Mother River of Vietnam or Yuan River of China that flows from south western China through northern Vietnam to the Gulf of Tonkin.

The Red River begins in China's Yunnan Province in the mountains south of Dali.it passes through Dai ethnic minority areas before leaving China through Yunnan's Honghe Autonomous Prefecture.The reddish-brown heavily silt-laden water gives its name . It is known as notorious for its violent flood.
The Black River and Lo River are its two tributaries.
The Red River Delta, a flat, triangular region of 3,000 sq.kms, is smaller but more intensely developed andf densely populated. than the Mekong delta.It accounts for 70 % of the agriculture and 80 % of the Industry of North vietnam before 1975.
