View of the Dom Luis I bridge over Douro River and Rabelo boats aligned with colourful buildings, UNESCO World Heritage Site, Porto, Norte, Portugal, Europe

photography horizontal color image travel destinations travel outdoors day no people portugal europe douro river river water dom luis i bridge bridge architecture city urban scene building rabelo boat boat porto cloud sky travel destination tourist destination tourist destinations skies rivers flowing water outdoor outside nobody no one no person daytime cities urban buildings bridges connection connections nautical vessel nautical vessels transport transportation architectural