Dom Luis 1 bridge over the River Douro, Cais de Ribeira waterfront, with Vila Nova de Gaia opposite, Oporto, Portugal, Europe

arch architecture bridge bridging cais de ribeira cais de ribeira waterfront color image day dom luis 1 bridge horizontal motion nobody oporto outdoors photography portugal spanning town transportation travel travel destinations urban vila nova de gaia waterfront arc bridged city color colour crossing daytime eu eu europe european european union joining metropolitan movement outside portuguese south west europe southern european transporting village water