On the southern coast of Yonaguni, Japan, lie submerged ruins estimated to be around 10,000 years old. The origin of the site is hotly debated - many experts argue that is man-made, while more conservative scientists insist it was carved by natural phenomena.
The unique and awe-inspiring site was discovered in 1995 by a diver who strayed too far off the Okinawa shore and was dumb-struck when he stumbled upon the sunken arrangement of monolithic blocks "as if terraced into the side of a mountain". The structure sparked instant controversy and attracted crowds of diving archaeologists, media and curious hobbyists, none of whom were able to ascertain its identity.
Late in the following year, more serious attempts were made to gather data and map out the structure. The process revealed many surprising findings including what appears to be a massive arch or gateway of huge stone blocks which appeared to fit together perfectly, right angled joins, carvings and what appeared to be stairways, paved streets and crossroads and grand staircases leading to plazas surrounded by pairs of towering features resembling pylons.
As teams of expert divers fanned out from the south coast of Okinawa using grid-search patterns, they found five sub surface archaeological sites near three offshore islands. The locations vary at depths from 100 to only 20 feet.