The Red River (Chinese: t 紅河, s 红河, p Hóng Hé; Vietnamese: Sông Hồng), also known as the Hồng Hà and Sông Cái (lit. "Mother River") in Vietnamese and the Yuan River (元江, Yuán Jiāng) in Chinese, is a river that flows from Yunnan in southwest China through northern Vietnam to the Gulf of Tonkin. According to C.