Ключевые слова: abandoned, cable, collector, communication, concrete, connect, connection, construction, corridor, deep, electric, electrical, electricity, empty, engineering, factory, fiber, heating, highvoltage, industrial, inside, interior, lamps, light, line, maintenance, metal, metro, modern, optic, passage, perspective, phone, pipeline, railroad, russia, sewer, steel, subterranean, subway, technical, technology, traffic, transportation, tunnel, underground, urban, wiring,