Is the Mysterious Yonaguni Monument Japan’s Own Atlantis?

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  • When I was a kid, I was obsessed with aliens and the unexplained. I remember getting a book from the library about unexplained phenomena: the Bermuda Triangle, the Mary Celeste, Bigfoot, the Loch Ness Monster, and much, much more. In the book, there was a short chapter on a topic that combined two things I love – mysteries and Japan. This chapter was about the Yonaguni (与那国) Monument, the mysterious seemingly underwater city off the coast of Japan. Theories about what this site and who built it range from the mundane to pants-crappingly insane. If some of the theories about it are correct, it will rewrite everything that we know about human civilization.

    What is the Yonaguni Monument? Who found it? Who built it? Or is it a natural formation? Finally, what does Yonaguni mean to our understanding of human history?

    (Special thanks to the Blurry Photos podcast for reminding me of this fascinating discovery and for making such a fun and entertaining podcast.)


    The Island of Yonaguni is just miles away from Taiwan and is the last island in the Ryukyu island chain (琉球諸島). It is the westernmost inhabited Japanese island. In the ice age, Yonaguni Island was part of the Chinese mainland, but due to rising oceans and land shifts, it became one of the many islands that were spread out in between China and the Japanese home islands. It was once part of the Ryukyu Kingdom (琉球王国) until it was overtaken by Japan, then it was much later taken over by the American government after the succession of WWII. It was given back to Japan with Okinawa (沖縄) in 1972. It remains today part of the Okinawa Prefecture.

    Much of Yonaguni’s economy is based on tourism. Many local guides take tourists on beautiful scuba diving trips. The area is a breeding ground for hammerhead sharks and has beautiful water and reefs. Local guides often explore new areas to take tourists to, and it was on one such expedition that Kihachiro Aratake (新嵩喜八郎), a local leader on the island’s tourism board, noticed some strange irregularities on the seabed.

    In 1985, Aratake went scuba diving to check out this area and came upon a sight that took his breath away (very dangerous underwater) – large pieces of rock seemingly cut at near perfect angles, and forming what seemed to be like a step pyramid structure. This structure is generally rectangular in shape and measures at roughly 100 meters by 60 meters and is over 25 meters tall! Gigantic!

    He immediately reported his discovery to any source he could, but no one seemed to be very interested. Some time later, the University of the Ryukyus (琉球大学) sent out Professor Masaki Kimura (木村政昭). He and Aratake went diving to check out the anomaly, and Kimura determined that not only the structure was man-made, but it was the construction of a previously unknown prehistoric civilization. A civilization that would have to have been rather technologically advanced to create such a structure. He claimed that the underwater city was built over 10,000 years ago and sunk into the sea (he did later walk that theory back to only 2,000-3,000 years).

    What was this “city”?

    Professor Kimura postulated that the entirety of the site was carved of one bit of underlying sandstone. In an interview about the monument, Professor Kimura said the following:

    “These are ruins, and to me, the fact has already been proved. The scientific conclusion is that the ruins are indeed artificial (Man made). A school of Japanese marine geologists agreed on this outcome. We found that the ruins are at least 6000 years old. It could go back another 4000 years when we consider the length of time before they sank into the water. … During the past 10,000 years, the ocean water level rose about 40 meters. From this fact, it is only natural to think that the ancient civilization is now deep in water. Drills we use to investigate ruins have improved recently, so with the help of the latest equipment, we will have a scientific conclusion on this matter in the near future.”

    Professor Kimura theorizes that this was not a city, but a ritual complex. He points out various areas that he believes are structures meant for ceremonial purposes only. Before you shrug off this theory entirely saying, “Why would a culture spend so much time creating a giant monument with no real purpose in mind?” Consider, what is the purpose of the pyramids in Egypt? Or for that matter, what good is the formation of Stonehenge? Or even, how does the Statue of Liberty help you? Nearly all cultures create monoliths for one reason or another. The unbelievable thing here isn’t that a group of people would build a giant monument, but the scale and time period. If Dr. Kimura is correct, then that would upset every commonly accepted theory of the rise of human civilization.

    Who built it?

    Professor Kimura claims that there is a lost civilization that existed when there was a land bridge connecting China, Taiwan, and Japan. This civilization grew and was very advanced, but then some sort of catastrophe occurred that caused this civilization to be lost to the annals of history. Kimura does not only base his theories on the monument itself, but on similar carving practices by civilizations around the area.

    Dr. Robert M. Schoch, professor of science at Boston University, takes umbrage at Kimura’s theories. He claims that the monument was not man-made at all, and is actually a strange by-product of the unique properties of sandstone and ocean currents. He said the following, “During my own research on the Yonaguni Monument, one of the first things I found is that the structure is, as far as I could determine, composed entirely of solid ‘living’ bedrock. No part of the monument is constructed of separate blocks of rock that have been placed into position. This is an important point, for carved and Arranged rock blocks would definitively indicate a man-made origin for the structure – – yet I could find no such evidence.”

    There are others who disagree with both Kimura and Schoch. They claim intervention by a higher power.

    The Dragon’s Triangle and Ancient Aliens

    You have probably heard of the famous Bermuda Triangle, an area that seemingly causes the mysterious disappearances of both water and aircraft for hundreds of years. Some believe that this area is home to the mythical Atlantis or an area of intense alien activity. Off the coast of Japan, on the same parallel is what is known as the Dragon’s Triangle.

    The Dragon’s Triangle is an area that is well known for being a danger zone for ships and aircraft. There are many stories of the natives of the area seeing strange creatures or machines coming out of the sea. There are also stories from hundreds of years ago that speak of a “hollow ship” crashing off the coast of a Japanese island, and a strange-looking woman who the Japanese islanders were unable to understand collapsing on the beach. She held in her hands a box and would not allow anyone else to touch it. In some legends, the box contained the head of her lover, but some scholars point out that the descriptions do not sound like the boxes Japanese people typically carry heads in. (Here I have to stop and say, “What the?! Head boxes?!) No one knows what exactly was in the box. If legends are to be believed, could it be possible that the “hollow ship” was an alien ship, and perhaps the box was some sort of control box?

    Could it be possible that ancient aliens (possibly even the same ones that built Atlantis) built this ancient civilization that Kimura speaks about? It would also explain Schoch’s criticisms because of course, it wouldn’t match any form of construction as we understand it, because it is not human engineering.

    A Geoglyphic Solution

    Believe it or not, the aliens theory isn’t the craziest one out there. Some believe the site to be of full of geoglyphs. They measure the angles of the different ridges, edges, and lines of the monument. They then draw out straight lines to see what they connect to and create a picture or web. For example, if you measure out the lines from the Yonaguni Monument.

    We see the total area that the Japanese Empire had control of (the red line). Odd that it matches almost perfectly with the Yonaguni Monument. Perhaps the Empire of Japan in WWII was indeed trying to reconquer land that its ancient predecessors had owned many thousands of years before.


    While interesting and intriguing, I think that the truth of the Yonaguni Monument is much more mundane. Dr. Kimura’s theories have been largely disproven by many other scholars, even Dr. Kimura himself has had to revise his theories gravely due to new evidence. The geoglyphs, while interesting, are not evidence. I can connect straight lines and edges with a lot of things, but that does not really prove anything. And the ancient aliens? Once again, where is the evidence?

    The truth is probably what Schoch theorized. He mentioned that sandstone has the tendency to break on planes creating sharp edges and straight lines. This area is also prone to earthquakes and strong currents which do some really weird stuff with the seabed. Dr. Schoch says the following:

    “The more I compared the natural, but highly regular, weathering and erosional features observed on the modern coast of the island with the structural characteristics of the Yonaguni Monument, the more I became convinced that the Yonaguni Monument is primarily the result of natural geological and geomorphological processes at work. … I could not find any surface evidence (such as tool marks on the rock surfaces or carved blocks that had been moved into place) that, in my opinion, would substantiate [Dr. Kimura’s] contention of artificiality. Of course, I have had only a very short time to search for such evidence, and just because I did not find it does not mean it does not exist. However, at this time based on my own findings and analysis, I cannot agree with Dr. Kimura’s conclusion that the Yonaguni Monument is primarily a man-made structure. My current working hypothesis is that the Yonaguni Monument is primarily of natural origin; that is, it’s overall structure is the result of natural geological and geomorphological processes.”

    Dr. Kimura has claimed that the only reason for the heavy blowback of his theory is that it because it upsets the status quo of too many scholars, and they just don’t want to admit that they might be wrong. One could call back the story of Copernicus who was burned for having a theory that did not fit in with the commonly accepted theory.

    Be that as it may, there is a status quo for a reason. If out of 100 scientists, 99 say it’s a duck and one says it’s a dog, the outlier has to come up with a lot of conspiracy theories to explain why he is the single outlier. We can see this same thing at work in many other areas. The anti-vaccination movement and the anti-global warming crowd are two such examples.

    The Yonaguni Monument is most likely nothing more than an interesting anomaly. Stranger things have proven to be true in the past and who knows, the general conception of human history could just be very, very wrong…


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