Fifty-seven new caves, including one which could have been formed underwater five million years ago, have been found in Quang Binh province, the home of magnificent caves in central Vietnam, Thanh Nien News Online reported on Wednesday.

The provincial government announced on Wednesday that the caves were found by a team comprising 13 members of the British Caving Research Association and experts from Vietnam National University, foreign rangers and locals.

Among the new found caves, one stands out as it stretches nearly three kilometers and was probably formed around five million years ago under what used to be a lake. Most other caves are between 2-3 million years old.

Traces of strong currents are visible on the cave walls though the water is long gone.

Howard Limbert of the British Caving Research Association that the five million years old cave was named Hoa Huong after the husband and wife who helped with the discovery.

The association has been exploring caves in Quang Binh since 1990, creating a map to 311 of them, including the world’s largest cave Son Doong.

Limbert said his team had only explored a third of the limestone mountains in Quang Binh and they might find bigger caves than Son Doong in the future.

57 new caves, including five million years old, found in Quang Binh - Thai PBS English News