The Tâmega River is an international river, which begins in the Serra of São Mamede, in the province of Ourense (Galicia, Spain) and flows in Entre-os-Rios on the Douro River.

The Tamega river is tributary of the Douro River. From Verin, it flows south to the Portuguese city of Chaves. The tamega river flows in Chaves and is a very important historical river, which served as an invasion route for foreign armies intent on reaching he richer Southeren lands of Portugal. Rio Tamega always flows in the direction towards North-South, and serves as an international border with a distance of about 2km.