An extremely rare turtle was recently found in Viet Nam, it may be the last wild specimen on Earth.

Cleveland Metroparks Zoo today announced the discovery of a critically endangered turtle in northern Vietnam that previously was thought to be extinct in the wild. Experts from the Zoo’s Asian Turtle Program confirmed that they have identified the only known living specimen of a Swinhoe’s soft-shell turtle (Rafetus swinhoei) in nature.

Other than the turtle discovered by Cleveland Metroparks Zoo’s Asian Turtle Program, only three of the giant turtles are known to remain. Two of them are at zoos in China, and one is in the Hoan Kiem Lake in Hanoi. The Swinhoe’s soft-shell turtle is considered by many in Vietnam to be a national treasure.

According to folklore, the rare turtle has emerged at key points in Vietnam’s history. The legend says that in the 15th century, the giant turtle rose from Hoan Kiem Lake to reclaim a magical sword that was given to Emperor Le Loi to expel the Chinese army from Vietnam. Some people believe that the single, large soft-shell turtle that occupies the lake today is the very same turtle that retrieved the sword from the Emperor and returned it to God.

Hanoi residents often line the banks of Hoan Kiem Lake in hopes of spotting the legendary turtle, which some believe brings good fortune to those who see it.