Sơn Đoòng cave – Mountain River cave (Quảng Bình Province, Vietnam)

Sơn Đoòng cave is a cave in Phong Nha-Kẻ Bàng National Park, Vietnam, with a large fast-flowing underground river inside. The biggest chamber of Sơn Đoòng is more than five kilometers long, 200 meters high, and 150 meters wide. With these dimensions, Sơn Đoòng take the title of the world’s largest cave.