Depth: Approximately 100 ft (30 cm)
This ruin was found in 1987 by local divers in off the Coast of Yonaguni Island, the most southern of the Ryuku Islands in Japan; lie submerged ruins estimated to be about 10,000 years old. Many experts debate that is man-made, while more traditional scientists claimed that the construction is not man-made, and is a natural formation.
The structure sparked moment debate and drew crowds of diving archaeologists, media and curious hobbyists, none of whom were able to determine its identity. A squad of expert divers found that they are five subsurface archaeological sites near three offshore islands.
Professor Masaaki Kimura, a marine seismologist of the University of the Rykyus, stated that “Out a number of symbols, such as a plus sign and a V shape, that seems to indicate that human beings worked the stone and could have been made by wedge-like tools called Kusabi.”
While many of the features seen at Yonaguni are also considered in natural sandstone formations throughout the globe, the concentration of so many peculiar formations with perfect 90 degree angle, straight walls, stairs, columns and what seems to be a human face carved in the stone.