What is the Yonaguni Monument?
The Yonaguni Monument is a huge rock formation on the seabed off the southeast coast of Yonaguni Island, Okinawa Prefecture, Japan’s westernmost point, at depths of up to about 25 meters. It features step-like ledges, flat terraces, sheer right-angled walls and trench-like passages, and has drawn attention as a possible ancient ruin.
Discovery and investigation
In 1986, a local diver discovered the formation while looking for dive spots. From the 1990s, Professor Kimura Masaaki of the University of the Ryukyus and others investigated it, arguing that it shows signs of worked stone and artificial structures, and that it is an ancient ruin once on land that sank into the sea. It is sometimes linked with the lost continent of Mu.
Man-made ruin or natural formation?
Many geologists, however, believe that the sandstone in this area naturally tends to split along flat planes, and that waves and tectonic movement created the step-like formations. No conclusion has been reached, and the area is popular with divers from Japan and abroad as the “Underwater Ruins Point.”
