Đà Giang

Đà Giang, the Black River, winds through the mountains of northwestern Vietnam before joining the Red River. Its lower valley opens towards the plains around Hòa Bình, while upstream the river cuts through steep ridges. In 1426 Lê Lợi sent Lam Sơn commanders into the Đà Giang and neighbouring districts to obstruct the approach of Ming reinforcements from Yunnan during the struggle for Đại Việt.