Douro is a river which rises(originates) in Spain in 2 160 m of height, in the sierra of Urbin belonging to the Iberian mountain range. it winds through Meseta hanging 612 km. Then on 122 km, it marks the border between Spain and Portugal in a damaged region,its slope becomes more marked and its bed gets dug(grows bigger) between high granitic walls. Downstream to Barca de Alva, he becomes completely Portuguese on 206 last ones km of his course(price) and becomes navigable before throwing(casting) itself into the Atlantic Ocean in Porto