Hải Dương
Thái Bình river starts in the area of Đồng Phúc commune, Yên Dũng District, Bắc Giang Province - where the Thuong River and Cầu River join with each other. It then flows to Hải Dương Province and becomes the boundary between Bắc Giang and Hải Dương. After flowing through the area of Hải Dương, it enters Thái Bình Province and flows to the South China Sea at Ba Lat river mouth.