Douro

Douro (Span. Duêro), one of the largest rivers of Spain and Portugal, rises in the Pico de Urion (7369 feet), in Old Castile, about 30 miles NW. of Soria (3445 feet above sea-level). From its source it flows south-east to Soria, then winds towards the west, and pursues a general westward direction till it reaches the Portuguese border, when it flows south-west for about 60 miles, forming the boundary between Spain and Portugal, and then flows west through Portugal, entering the Atlantic below Oporto. Its Portuguese tributaries are comparatively small. The total length of the river is about 490 miles; it is navigable to Torre de Moncorvo, 90 miles.