Traditional boats on Vila Nova de Gaia bank of Douro River, Dom Luis I Bridge in the background, UNESCO World Heritage Site, Porto, Portugal, Europe

horizontal color image travel destinations travel copy space outdoors day porto portugal europe river douro river water dom lu?s i bridge arch bridge bridge transportation connection architecture oporto no people building exterior building clear sky sky city urban scene rabelo boat boat cargo boat past history unesco world heritage site unesco boats nautical vessel nautical vessels transport cities urban colour image color colour daytime nobody no one no person outdoor outside rivers flowing water travel destination tourist destination tourist destinations