Ключевые слова: abstract, amazing, ancient, asia, asian, background, beautiful, bo trach, cave, cavern, close up, color, formation, geological, geology, grotto, heritage, impression, impressive, indoor, inside, lamp, landscape, limestone, national, natural, nature, paradise, paradise cave, quang binh, quangbinh, scene, shape, speleology, stair, staircase, stalactite, stalagmite, stone, tourism, tourist, travel, underground, viet nam, vietnam, vietnamese, wonderful,