Son River - 4 Things to Know Before Visiting

Phong Nha Cave is a cave in Quảng Bình Province, Vietnam. It is 7,729 meters long and contains 14 grottoes, as well as a 13,969-metre underground river. Its cave system features underground passageways and river caves filled with stalactites and stalagmites. The stalagmites that used to stand at the cave’s entrance apparently inspired its name: Phong Nha means ‘Wind and Teeth’.

Phong Nha-Kẻ Bàng is a national park and UNESCO World Heritage Site in Quảng Bình Province of Vietnam. The park was created to protect one of the world's two largest karst regions with 300 caves and grottoes and also protects the ecosystem of limestone forest of the Annamite Range region in North Central Coast of Vietnam.

Thiên Đường Cave is 31 km long, longer than Phong Nha Cave which had been considered the longest cave in Phong Nha-Kẻ Bàng National Park. The height can reach 72 m and 150 m wide.

It is the largest known cave passage in the world by volume. The scale of this site’s interior is so massive it could fit an entire New York block inside, including skyscrapers, or have a Boeing 747 comfortably fly through without its wings being in any danger.

Phong Nha-Ke Bang National Park contains the oldest karst mountains in Asia, formed approximately 400 million years ago. Riddled with hundreds of cave systems – many of extraordinary scale and length – and spectacular underground rivers. It is designated as a Unesco World Heritage Site in 2003.

Hang En is the third largest cave in the world, after Hang Sơn Đoòng in the same national park, and Deer Cave in Malaysia. The only ways to reach the cave are by helicopter, or an approximately four-hour jungle trek from the nearest road.