Porto with bridge Ponte Dom Luis I over river Douro and tramway travel city in Porto, Portugal, Europe

arch bridges arch bridge architecture boats boat bridges bridge buildings building catedral cathedrals cathedral churches church cities city center city centre city portrait city railways city railway cityscape city scape city traffic city view city constructions construction cultural monuments cultural monument cultural sites cultural site deserted douro river douro downtown duero empty europe famous place gustave eiffel heritages heritage historical historic center historic centre historic city center historic city centre historic old town historic holidays holiday time holiday inner city inner town journey local traffic local view midtown nobody no one no people northern portugal old quarter old towns old town ol overviews overview passenger traffic passenger transports passenger transport place of interest ponte dom luis i bridge ponte dom luis i ponte porto portugal portuguese public transport rail traffic religious building rio douro river rio douro rivers river roads road traffic road sacral building sacred building ships ship short range public transportation short range transit sights sight skylines skyline southern europe south europe stadtbahn steel buildings steel building streetcars streetcar street tourism tourist attractions tourist attraction town center town centre townscapes townscape town view town traffic tramway tram traveling travel photography travel trip unesco world heritage sites unesco world heritage site unesco world heritage unesco uninhabited vacation time vacation vessel view of the city village world heritage site