Ключевые слова: architecture, blue, bridge, building, center, city, cityscape, commercial, day, dom, douro, downtown, europe, historic, history, house, landmark, light, luis, luiz, metro, modern, old, oporto, people, ponte, porto, portugal, portuguese, rail, railroad, railway, river, sky, station, subway, summer, tourism, train, tram, transport, transportation, travel, urban, vehicle, view, yellow,