Ключевые слова: age, ali sadr, alisadr, alofaaga, ancient, apostle islands, cathedral cove, cave, cavern, caving, cenote dos ojos, chandelier, crystal, cuevas de marmol, deep, down, europe, fingal, formation, geological, great blue hole, grotto, grotto azzurra, hamedan, inside, interior, iran, kuredu, light, lime, liquid, million, natural, nature, old, orda, reflection, rocks, sea lion, shale, smoo, stalagmites, stones, surface, tourism, travel, underground, underworld, usa, year,