Ranked No. 5 on this list, the magazine described Phong Nha as a beautiful cave with stalagmite systems and spectacular stalactites.

The magazine writes “Phong Nha’s magnificent grottos are filled with spectacular stalagmites and stalactites and are distinctive examples of a complex karst landform. This has resulted in underground rivers and the development of a maze of caves.”

It notes “Phong Nha is also a fossil-rich site and a location where new caves are still being discovered.”

Phong Nha cave is located in the province of Quang Binh, in North Central Viet Nam, 500 km south of Ha Noi.

This cave has long been known as a unique wonder with seven criteria: The longest water cave, the highest and widest cave mouth, the widest and most beautiful sand & rock bank, the most beautiful underground lake, the most magnificent and miraculous stalactite, the nation’s longest underground river and the nicest and widest dry cave.

Other caves in the list are Waitomo Cave (New Zealand), Indian Caverns (United States), Dan-yr-Ogof Cave (Wales), and Eisriesenwelt (Austria).