Ключевые слова: architecture, building, center, city, cityscape, culture, day, destination, douro, downtown, europe, european, famous, fooftop, historic, historical, horizontal, houses, landmark, old, old town, oporto, part, picturesque, place, port, porto, portugal, portuguese, red, river, river bank, riverside, roof, site, skyline, tourism, town, travel, unesco, urban, view, world heritage site, world locations,