Abstract background A three-dimensional metal tube construction. pyramidenkogel, tower, austria, observation, worth, design, sky, travel, landscape, architecture, view, building, metal, wood, construction, high, wooden, steel, mountain, landmark, famous, tall, unique, tube, step, slide, broadcasting, wires, tallest, villach, carinthia, structure, maria, wooden-steel, flags, interior, top, attraction, elevator, rails, destination, europe, stairs, steps, up, down, senses, height, feelings, summit