The Mysterious Sunken “Pyramid” of Japan

The Yonaguni Monument is a massive underwater rock formation off the coast of Yonaguni, the southernmost of the Ryukyu Islands, in Japan. While many archaeologists and geologists believe that it is a natural formation, some hold the view that some of its features are man-made.


A mysterious undersea pyramid structure off the coast of Japan causes controversy – is this a natural geological phenomena or a man-made structure which changes the history books as we know them?

In 1986, a diver near the island of Yonaguni Jima, off the southern tip of Japan (around Okinawa) came across some strange structures about 25 metres below sea level.
They appeared to be stepped structures with terraces and ramps.
One of the largest pyramid structures is 600 feet wide and 90 feet high –with five separate levels of stone blocks with what appears to be road surrounding the structure.

Tool marks and carvings have been discovered upon the stones (and documented) which indicate that they have were constructed rather than being natural stone structures.

Masaaki Kimura, a marine geologist from Japan’s Ryukyus University, Japan has been studying and mapping the site for over 15 years and believes that the site is over five thousand years old – but was sunk during an earthquake two thousand years ago.

Others have estimated that the structure is far older – including Teruaki Ishii, professor of geology at Tokyo University who determined that the submergence occurred at the end of the last ice age – which was around ten thousand years ago (over twice as old as the pyramids in Egypt) – If this is the case, then our history books would have to be revised to take into account an advanced Eastern culture, more advanced than any early Western culture.

It is interesting to note that a number of tools have been discovered both on land and in the sea around the structures.

Close to the pyramid structure, what is thought to be the carving of a human head has been discovered (several feet tall), along with numerous unknown hieroglyphs

The Japan Times reported the following story to add intrigue to the find

 “In Okinawan folk-law, there are tales of traditional Gods , and a land of the Gods called Nirai Kanai, an unknown faraway land from where happiness is brought.”


Richard Schoch – Professor of science and mathematics at Boston University does not accept that the site is anything other than a natural rock formation

“I’m not convinced that any of the major features or structures are manmade steps or terraces, but that they’re all natural,”

“It’s basic geology and classic stratigraphy for sandstones, which tend to break along planes and give you these very straight edges, particularly in an area with lots of faults and tectonic activity.”

The photograph below shows what is believed to be a similar natural rock formation on land

As a consequence of the scientific community’s reluctance to accept the site as a man made structure, the ruins have not been recognized by Japanese officials as a site of cultural importance, worthy of protection or further research.

On 5th April 1998, a massive earthquake (measured at 7.7 on the Richter scale) hit the area around the pyramids – whether the underwater structures were damage or not is not clear.



Unfortunately, until further studies are carried out on the structure, it will remain a site of speculation and contention.

There are two sides to consider, both have an agenda

* Scientists / Historians – reluctant to accept any evidence which alters their current, widely accepted human timeline.

* Those who are keen to promote the area as a tourist attraction.