The Yonaguni Monument, an enigmatic underwater structure near Japan’s Yonaguni Island, has intrigued scientists and explorers ...

said he believed the Yonaguni Monument (as it’s now known) is not manmade at all. Referring to its platforms and terraces, he told National Geographic: "It's basic geology and classic ...

Beneath the coastal waters of the Japanese island of Yonaguni lies a series of mysterious ... or is it just a stunning example of natural geology deep beneath the sea? Video by Naotomo Umewaka ...