europe, portugal, porto, city, european city, ribeira, old town, old city, square, landmark, river, douro, douro river, bridge, ponte, ponte de dom luis, dom luis, golden hour, brown, taken, aerial, train, grey, photography, gray, metropolis, landmass, stream, district, urban area, aeriform, european country, urban center, sundown, ethereal, sunset, port, rectangle, public transport