Japan’s Atlantis? The 12,000-year-old mystery beneath the sea
- Paul Aage Hegvik
- Apr 12
- 4 min read
Off the coast of Yonaguni Island in Japan’s Okinawa Prefecture lies a submerged structure that has captivated scientists, divers, and theorists alike.
Known as the Yonaguni Monument, this underwater formation features massive stone terraces, sharp angles, and flat surfaces that resemble a man-made pyramid. The Yonaguni Monument was first discovered in 1986 by Kihachiro Aratake, a local diver and director of the Yonaguni-Cho Tourism Association.
While scouting for new dive sites off the coast of Yonaguni Island in Okinawa, Japan, Aratake noticed strange formations beneath the surface — large flat terraces, sharp angles, and what appeared to be steps cut into the rock.
He later described the moment:
«I thought at first it was just a natural rock formation. But the more I looked, the more it seemed like something made by people.» Kihachiro Aratake Discovered the monument in 1986
His discovery sparked decades of investigation, debate, and fascination, drawing in marine geologists, archaeologists, divers, and ancient civilization theorists from around the world.
A discovery beneath the waves
Aratake stumbled upon the structure while searching for new diving spots. Measuring approximately 164 feet in length and 65 feet in width, the monument's design includes spiraling steps and flat platforms. «I was very emotional when I found it,» Aratake recalled. «I realized that this would become a treasure of Yonaguni Island.»
«I was very emotional when I found it. I realized that this would become a treasure of Yonaguni Island» Kihachiro Aratake
Theories and Debates
The monument's origin remains a topic of contention. Marine geologist Masaaki Kimura from Ryukyu University argues that the structure shows signs of human influence, suggesting it could be remnants of an ancient civilization. «I think it's very difficult to explain away their origins as being purely natural,» Kimura stated.
Conversely, other experts believe the formation is a natural geological occurrence. Geologist Robert Schoch from Boston University contends that the monument's features result from natural processes, such as tectonic activity and erosion. «The rocks of this group are also criss-crossed by numerous sets of parallel, vertically oriented joints in the rock ... These joints are natural,» Schoch explained.
Japan’s pre-ice age underwater pyramid continues to stir scientific debate, raising fresh questions about whether it could truly have been built by humans — or if its origins lie in a deeper, still-unexplained chapter of Earth’s history.
«Japan’s Atlantis»
The Yonaguni Monument is frequently called «Japan’s Atlantis» due to its massive, temple-like appearance beneath the sea. However, debate continues over whether the formation is the work of an ancient civilization or simply the result of natural geological processes.
The discussion recently resurfaced after a high-profile exchange between author Graham Hancock and archaeologist Flint Dibble on an episode of the Joe Rogan Experience in April 2024, where the site's origins were hotly contested.
«I've seen a lot of crazy natural stuff and I see nothing here that to me reminds me of human architecture,» Dibble said on the podcast in April 2024.
A Diver's perspective
Diver Kenzo Watanabe, who explored the site, remains convinced of its artificial origins. «After seeing it, there's no ... ,» Watanabe said. «Especially with all the flat surfaces ... .»
The ongoing mystery
The Yonaguni Monument continues to intrigue and puzzle researchers. Whether it's a natural formation or evidence of a lost civilization, the structure challenges our understanding of history and human development. As investigations persist, the monument remains a symbol of the mysteries that lie beneath the ocean's surface.
For those interested in exploring this enigmatic site, Yonaguni Island offers diving tours to the monument, providing a firsthand glimpse into one of the world's most fascinating underwater mysteries.
Facts - Yonaguni Monument
Discovered: 1986 by diver Kihachiro Aratake
Location: Off the south coast of Yonaguni Island, Okinawa Prefecture, Japan
Depth: Approx. 25 meters (82 feet) underwater
Size: Around 150 meters long, 40 meters wide, 27 meters high
Appearance: Terraces, steps, flat surfaces, and sharp corners resembling a pyramid or ziggurat
Age (if man-made): Estimated up to 10,000–12,000 years old
Debate: Scholars are split — some say it's a natural sandstone formation shaped by tectonic activity, while others claim it's man-made, possibly from a lost civilization
Features: Possible carvings, roads, what appear to be pillars, platforms, and even a «face»
Theories: Linked to ancient Pacific cultures, Atlantis-like civilizations, or natural seismic activity
Visibility: Popular diving site with guided tours from Yonaguni Island
Facts - Yonaguni Island
Location: Japan’s westernmost inhabited island, part of Okinawa Prefecture
Distance: About 125 km east of Taiwan
Population: Around 1,700 residents
Main village: Sonai
Languages: Japanese and Yonaguni (a Ryukyuan language)
Geography: Rugged coastline, coral reefs, forested hills, and open plains
Economy: Primarily fishing, sugarcane farming, and tourism
Wildlife: Known for Yonaguni horses — a native, semi-wild pony breed
Access: Flights from Okinawa’s main islands and ferries (though infrequent)
Notable for: Yonaguni Monument diving, whale watching, traditional weaving, and being the last place in Japan to see the sunset each day
