Son Doong (Sun pickle) Ancient cave hidden within the Valley. With 150 meters to 200 meters in width and has a length of up to 9 kilometers, who wants to try is this cave explorers meet lots according to see greatness more, the world's largest cave Son Doong Cave Viet Nam country capacity building Empire to friends. It is now a top 10 trips at the travel lovers need to visit at least once in your life!