Ключевые слова: black, cave, coal, construction, copper, corridor, dark, dig, dirty, energy, engineering, entrance, equipment, escape, geology, gold, historical, history, indoor, industrial, industry, inside, interior, iron, light, machine, machinery, metal, mine, mine drill, miner, mineral, mystery, old, railroad, railway, rock, silver, stone, technology, tool, train, tunnel, tunneling, underground, wagon, way, working,