Underwater monument

The mysterious underwater monument off the coast of Yonagunijima was discovered in 1986 by Sou-Wes founder and divemaster Kihachiro Aratake when he was scouting the seas around the island for new hammerhead shark-watching points. The discovery sparked a debate as to whether they are naturally formed or manmade structures created by an ancient civilization.

If the monument is indeed manmade or modified by man, that would date it back to the last Ice Age, around 10,000 years BC, when the sea level was 40m lower than it is now and Yongunijima was part of a land bridge connecting Japan, Taiwan and the Chinese mainland. This would make the monument the oldest man-made artifact on earth, significantly pre-dating the pyramids in Egypt.

While there are arguments for and against this view, most divers – including numerous scholars as well as the late skin diver Jaques Mayol who visited the island and wrote a book about the monument – are convinced that they are manmade structures when they see them with their own eyes.

Key features of the site include perfectly perpendicular terracing reminiscent of terracing at Incan sites, a staircase, two megaliths standing side by side, a triangular-shaped pool with a drainage channel, a room carved out of the rock, decorative rock carvings and a formation which looks distinctly like a face, reminiscent of the famous heads at Easter Island. The precision of the terracing and sheer number of peculiar features gathered in one small area suggest that the monument can only have been manmade or modified by man. Is it the key that will unlock the secrets of an ancient, long-lost civilization? Come and experience the eerie beauty of these mysterious undersea structures and judge for yourself.