Ключевые слова: america, attraction, beautiful, big, blue, calcite, carlsbad, cave, cavern, column, dark, formation, geological, geology, inside, landmark, large, limestone, luray, mexico, mineral, mountain, national, natural, nature, new, nobody, park, reflection, rock, room, shenandoah, southwest, southwestern, speleology, spelunking, stalactite, stalactites, stalagmite, stalagmites, stone, subterranean, tourism, travel, underground, united, usa, valley, virginia, water,