The caves were discovered in Phong Nha Ke Bang National Park in Quang Binh Province during a six-week expedition with a team consisting of 12 cavers from the UK and one from Australia. The area is famous as the home of the world’s largest cave, Son Doong Cave.

Howard Limbert of the British Cave Research Association led the expedition team, which has been exploring caves in the area since 1990, during which they have discovered what is currently the world’s largest cave as well as the world’s longest river cave.

On this latest expedition, the team surveyed and photographed over 20km of new cave passage, Howard said.

Teams normally spend up to eight days in the remote jungles of the National Park, with assistance from the local people in finding the cave entrances, which are often difficult to locate and access.

There are already plans to open some of the new caves to tourists in the very near future, according to local reports.

One of the 57 new caves, Hang Hoa Huong, is said to have formed underwater five million years ago and is 2876m long. It is said to have the most potential for future tourism.

Pictured is the main passage of another one of the 57 new caves, Hang Tien, which is 2519m long.

The main passage of Hang Tien. On the expedition, the explorers, including one Australian, were accompanied by a local pilot as well as experts from the national park and Hanoi National University.

According to expedition leader Howard Limbert, the team plans to return to continue to explore more unfinished caves in the area in 2017.

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