Dubbed “Japan’s Atlantis,” the Yonaguni Monument has sparked intense debate since its discovery in the 1980s. Theories about its origin range from natural formation to the possibility of it being a man-made structure created by an ancient civilization, yet its true nature remains elusive.

Background

In 1986, diver Kihachiro Aratake stumbled upon the structure while exploring the waters off Yonaguni Island in Okinawa. What he encountered resembled a pyramid, exhibiting multiple steps or layers leading to the top, with clean, symmetrical edges and angles. Standing 25 meters tall, 100 meters long, and 60 meters wide, the rock is composed of shale and sandstone dating back 20 million years, covering an area of approximately 45,000 square meters.

Ancient civilization?

Researcher Masaaki Kimura from the University of the Ryūkyūs posits that the structure is a series of monoliths constructed by humans around 10,000 years ago, possibly part of the lost continent of Mu. Mu, a mythical land akin to Atlantis and Lemuria, is said to have sunk beneath the Pacific due to cataclysmic events, with survivors spreading across the globe and founding ancient civilizations. However, this theory is often dismissed by academics as conjecture or myth.

Kimura supports his claims with various pieces of evidence, including the presence of possible animal-like statues, rock carvings, and formations resembling man-made features. Some speculate that the Jōmon people, ancient hunter-gatherers of Japan, could have built the monument.

Nature at work?

On the other hand, geologist Robert Schoch of Boston University contends that the monument is a result of natural processes, citing well-defined parallel bedding planes and jointing in the rock that create symmetrical formations resembling steps and walls. He argues that these formations are not uncommon in sandstone and are shaped by erosion and strong currents.

Conclusion

Despite two major expeditions to the site in 1986 and 1997, no definitive conclusion has been reached. While the structure’s appearance suggests deliberate construction, challenges such as the inability to ascend the steps and the possibility of pareidolia—the perception of patterns where none exist—cast doubt on its artificial origin. Additionally, the historical credibility of the lost continent of Mu is questioned.

As the Yonaguni Monument lacks special protection from the Japanese government, divers continue to explore it freely, forming their own interpretations and theories about its enigmatic existence.