Flowing from China through Vietnam to the South China Sea, the Red River (Vietnamese Sông Hồng, Chinese Hónghé) is also known as the Yuan Jiang (元江, pinyin yuan2jiang1), which means "Primary River."

The river begins at Erhai Lake, in China's Yunnan province. It flows generally southeast, and leaves China through Yunnan's Honghe Autonomous Prefecture. It enters Vietnam through Lao Cai province, and eventually passes by the eastern edge of the Vietnamese capital Hanoi. Tonkin is located on the river delta. In colonial days, the French and other powers attempted to establish the Red River as a trading artery with China, with some success.

In Yunnan China, settlements along the river include Honghe and Yuanyang.

See also: Geography of China