Ключевые слова: 20th century, air, architecture, austria, austrian, aviation, bomb, bomber, building, bunker, castle, city, concrete, day, defense, earth, exterior, flak, fortification, fortress, garden, green, historic, historical, historical building, history, hitler, landmark, massive, military, nazi, nobody, old, park, reinforced concrete, reminder, remnant, shelter, sky, spring, springtime, structure, tour tourism, tower, town, travel, vienna, war, world war ii,