Ключевые слова: action, active, adventure, back, backpacker, boy, building, city, discovering, down, elevator, entrance, going, level, lifestyle, lift, machinery, male, man, metro, modern, motion, move, movement, outdoors, passenger, people, person, place, porto, portugal, public, spot, standing, subway, technology, teenager, tourism, tourist, town, transport, transportation, travel, traveler, traveller, trip, underground, urban, visiting, young,