What is the name of the Red River in Vietnam?

Heihe river. The Red River is called Heihe River in Vietnam. It is a cross-border water system from Yunnan Province in China to Viet Nam. It is the only important international river originating in Yunnan (with the border of Hekou Town, Hekou County, Honghe Prefecture, Yunnan Province, China) and the largest river in northern Vietnam. The Red River Delta is the main economic zone in northern Vietnam.