Ключевые слова: 180, 360, abandoned, asen, blue, bulgaria, copper, crater, danger, deep, degrees, diamond, dig, earth, ecology, environment, excavation, geology, gold, heavy, hole, industry, iron, metal, mine, minerals, mining, mountain, near, open, openpit, ore, panorama, pit, quarry, rock, site, sky, spherical, stone, tsar, village, water,