The Ma River (Vietnamese: Sông Mã, Lao: Nam Ma) is a river in Asia, originating in northwestern Vietnam.It rises from Dien Bien Phu, flows through Laos, fall into Thanh Hoa territory at Muong Lat District, flows thorough Ba Thuoc, Cam Thuy districts and to Vinh Loc District.
The Ma River creates the Ma River Delta (also called the Thanh Hoa Delta), the third largest in Vietnam. At there Ma river flows through Vinh Quang, Vinh Yen, Vinh Tien, Vinh Thanh, Vinh Ninh, Vinh Khang communes, covers the whole of northwest to southeast of buffer zone. The history revealed that many historic events of Tran-Ho dynasties happened on this river segment with the name as Loi Giang River.
Under construction of Tay Do imperial city, Ho Dynasty used Ma River as waterway transport line to carry materials, commercial exchange, at the same time it was a place of sightseeing for King and mandarins of royal dynasty. Geographical names such as Ben Da (Tho Dong Hamlet – Vinh Yen Commune), Ben Ngu (Phu Linh Hamlet – Vinh Tien Commune) and Ben Giang (Giang Village – Vinh Thanh Commune) exist until now to show operation of Ho Dynasty on this river segment. On the other hand, Ma River was used by Ho Dynasty as natural external defensive line to defend Tay Do Imperial City.