Ключевые слова: abandoned, alone, architecture, circulation, concept, concrete, construction, corridor, creepy, danger, dark, darkness, deep, dirty, drainage, duct, ducting, ductwork, dungeon, engineering, exploration, explorer, exploring, factory, heat, heating, horror, indoor, industrial, industry, inside, interior, light, line, main, man, pipe, pipeline, round, sewer, spooky, steel, subterranean, system, tube, tunnel, underground, urban, warm, work,