Ключевые слова: ancient, attraction, beautiful, cave, cavern, caving, column, dark, deep, europe, formation, geologic, geology, grotto, hall, inside, interior, jama, karst, limestone, mineral, mountain, national, natural, nature, nobody, postojna, rock, slovenia, speleology, stalactite, stalagmite, stone, tourism, travel, tunnel, underground, vertical, wall, water,