Phong Nha-Ke Bang is located in a limestone area of ​​about 201,000 hectares in the territory of Vietnam, the Laotian territory adjacent to this national park also has an area of ​​​​about 200,001 hectares of limestone mountains. This national park is set up to protect one of the two largest karst regions in the world with about 300 caves and preserve the northern Truong Son ecosystem in the North Central region of Vietnam. Features of this national park are limestone formations, 300 caves, underground rivers and rare flora and fauna listed in the Red Book of Vietnam and the Red Book of the World. Hang Son Doong is recognized as the world's largest cave with and Phong Nha cave with limestone and sedimentary tectonics.