Ключевые слова: adventure, ancient, attraction, background, beautiful, big, calcite, calcium, cave, cavern, caves, caving, crystal, dark, deep, earth, entrance, environment, exploration, formation, geological, geology, hole, huge, inside, interior, karst, landscape, large, light, limestone, mineral, mountain, national, natural, nature, old, park, rock, speleology, stalactite, stalagmite, stone, tourism, tourist, travel, tunnel, underground, usa, water,