Phong Nha cave is located in the cave complex of Ke Bang limestone mountain in western Quang Tri. The cave consists of two parts: the dry cave and the water cave. Dry caves more than 200 meters high. This is an exhausted underground river with only stalactite white stone arches, countless iridescent jade green stone pillars. The cave is an underground river flowing day and night under limestone mountains connecting Ke Bang and primeval forests. The water here is very deep and very clear. The main cave consists of fourteen interconnecting chambers. The outer chamber is 10 meters from the water surface, from the fourth chamber of the cave, 25 to 40 meters high. Here there are stone blocks with many shapes, richly colored. There is a chicken-shaped block, a toad-shaped block, a block lined up on a vertical bamboo, some a raspberry-shaped block, a cube-shaped piece of a paper, and a block of the elves sitting on the chessboard, ... All create a fanciful beauty in color, sparkling like diamonds of the cave. In the cave, there are still green orchid branches, sandy beaches, rocky beaches, mysterious unspoiled alleys. The drops of underground water are flowing like the sound of a guitar, the bell in the temple scene, the land of the Buddha.