Photo by Luke Short
Kevin Short / Special to The Daily Yomiuri
I’m a sucker for ancient mysteries. I’ll sit glued to the TV for hours watching shows debating the location of Atlantis, the true age of the Sphinx or the origin of the huge statues on Easter Island.
Japan also has its share of ancient mysteries. Small but well-preserved stone circles have been found at various sites, and Kuromanta, a low conical hill in Akita Prefecture, is believed by some scholars to be a stepped pyramid covered with earth.
Japan’s world-class ancient mystery, however, lies way to the south. Just off the shore of tiny Yonagunijima island in the southernmost part of Okinawa Prefecture lies an incredible landscape: Rising from depths of 25 meters almost to the surface is an immense structure of fine sandstone. Nearly 250 meters long and 100 meters wide, the structure is cut into series of flat, level terraces, connected by steps with perfect right-angle walls and corners.
Local professional scuba diver Kihachiro Aratake first spotted this marvel in 1986, while searching for good spots to take his scuba diving tours. His immediate impression was that the structure was just too neat and sharp-angled to be the result of natural erosion. To him it looked more like ancient ruins, like those found at Machu Picchu, Peru.
In the 20 years since Aratake’s discovery, the Yonaguni Monument has become the center of an international controversy. Marine geologist Prof. Masaaki Kimura of Ryukyu University has spent more than a decade conducting scientific investigations in and around the site. His conclusions: The monument is a ceremonial center built on land by an ancient civilization, probably at the very tail end of the last glacial period about 10,000 years ago. Later, as the global climate warmed, melting ice caused the seas to rise, covering the monument.
Stalagmite caves, which can form only on land, have been found on the Ryukyu Islands seabed at depths equal to or greater than the base of the monument. This vindicates Kimura’s assessment that the monument would have been on dry land about 10,000 years ago. Some scholars, however, believe that the entire structure is not man-made at all, but simply the result of natural forces.
Had the Yonaguni Monument been, like Machu Picchu or the Egyptian pyramids, built of stone blocks that had been cut and fitted neatly in place, there would be no controversy surrounding its origins. The problem, however, is that all the neat steps and terraces appear to have been chiseled right out of the actual bedrock. Opponents of the man-made theory point out that fine sandstone tends to split open along flat fracture planes, and that the powerful currents off the coast of Yonagunijima island could have sculpted the monument after the rocks had sunk beneath the waves.
Archeology and anthropology also have their say in the debate. National Geographic’s amazing Genographic Project, which is using genetic mutations in Y-chromosomes and mitochondrial DNA to trace the movements of early modern humans across the globe, has identified a unique genetic mutation marker called M-174. This Y-chromosome mutation is one of the oldest. The people (Haplogroup-D) who carry it trekked from northern Africa along the coastlines of south and southeast Asia, then up the Ryukyu Islands to Japan. Even today, many Japanese men still carry this marker.
Skeletal remains of these early migrants have already been discovered in the Ryukyu Islands. The oldest of these has been dated to 32,000 years ago. Kimura’s time frame of 10,000 years ago thus presents no problem in terms of people being present in the Ryukyu Islands.
The issue, however, is that monumental architecture is normally associated only with economies based on intensive agriculture. In Japan, slash and burn dry-field farming is now documented to be at least as old as the middle Jomon Period (ca 10,000 B.C.-ca 300 B.C.), about 6,000 years ago, and settled villages in southern Kyushu have been dated to over 9,000 years ago.
Still, this Jomon agriculture is thought to have been small-scale, and only supplemental to the mainstay hunting, fishing and gathering economy. It was only at the very latest stages of the Jomon Period and beginning of the Yayoi Period (ca 300 B.C.-ca A.D. 300), no more than 3,000 years ago, that intensive cultivation of rice in irrigated paddies was introduced to Japan.
Even so, many of the structures associated with the Yonaguni Monument–two immense monoliths standing on edge side by side; a road at the base swept clear of all debris; round holes that may have held wooden pillars; a nearby rock carved into what from some angles resembles a human face–are cited as proof of a human hand in the making. In addition, rocks in the vicinity of the monument have been incised with lines that resemble primitive pictorial writing, and some human-made stone tools have been recovered from the area.
Taken together, all this evidence seems overwhelmingly in favor of the ancient undersea palace theory. Graham Hancock, famous explorer and author of such bestsellers as Fingerprints of the Gods, is convinced that this is the case, and uses the Yonaguni Monument as a lynchpin of his arguments that a sophisticated civilization existed more than 10,000 years ago, but that its monuments and cities have been inundated by the rising seas.
Critics, however, point out that taken one at a time, each supposed proof remains circumstantial and subject to doubt or at least closer scrutiny. No absolute irrefutable evidence of human work, such as fitted stone blocks or a burial chamber within the structure, has been located to date.
The Yonaguni Monument is a breathtakingly beautiful undersea landscape, and Yonagunijima island is a great scuba and ecotourism destination. As to the origin of the monument, my only advice is to go and see it, then decide for yourself!
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Related articles:
Underwater pyramids of Japan (Jan 22, 2009 Unresolved Mysteries of the World website)
Heritage of Japan 
Thank you for sharing this research. Given the clear evidence of Jomon artistry and the creation of large stone ceremonial areas, I have no trouble imagining that the Jomon could have carved the Yonaguni Monument. Many ancient human cultures, such as the Jomon, deserve much more attention and respect.
Yes, thank you for the article! I am doing a final project in college on Yonaguni, figuring all kinds of research had been done on it since I first heard of it 10 years ago. I’m actually quite surprised to see how *little* seems to have been done outside the new age crowd. Definitely interesting. Upon getting my Archaeology degree, perhaps the first grant I should pursue is further investigation of Yonaguni? 😉
I’d have to say that I am skeptical. I think that at best it could be mostly nature and a bit of man.
First, when we look at such sophisticated civilizations around the world as ancient Greece, Rome, and Egypt, we see landmarks that are vestiges of far-reaching peoples who also left their mark on language, other cultures, historical texts and so fourth. In this case, however, the Jomon, living as far back as twenty thousand or more years, built nothing even remotely similar in the rest of the archipelago and only started cultivating rice with the wave of immigrants from the peninsula and continent three hundred years before the common era, suggesting also that they had little contact with the outside world. And, as it turns out, the only hill-like pyramids that do turn up in Japan start showing up seventeen or so hundred years ago.
Too, the only evidence that we can see of anything that seems mad-made is straight lines and flat surfaces, however most of the ‘step’ structures are very irregular in terms of ‘stairs’, with one ‘step’ rising a foot and the next the length of a door and then the next a ‘step’ again.
How could a people “carve out” so much stone, suggesting that they would have had to live and be an . . . e nor mous culture, yet leave no other roadways or drainage systems or so fourth nearby? If it were an earthquake, the remaining civilization would have recorded such and left it as evidence, meanwhile the only evidence we have of anything even remotely like a religion for the Jomon people are their clay figurines and Venus pebbles, etc.. versus monumental sphynxes and so fourth.
My opinion is that if the area was ever exposed as land that primitive indigenous Jomon passers might have sometimes come to the site in awe and perhaps, like in caves, carved out shapes here or there.
It’s a mystery!
I agree that it’s most likely “a bit of nature and a bit of man”. The question to ask is how much of the “man” there was, when they arrived/left, where they came from, who they were and why they were there and left. We tend to think of the Jomon culture as one ethnic population which would be wrong, since the era spanned thousands of years, we ought to think of the Jomon culture as having been a culture resulting from the melting pot of various migrant arrivals. Who could have built Yonaguni is enigmatic, but in the light of genetic studies it is no longer preposterous to contemplate that any one of these ancient prehistoric lineages could have been the one: coastal lineages like M130 (haplogroup C), M174 (haplogroup D) or overland Eurasian-Central Asian-Siberian dispersals M175 (Haplogroup O) – all of these were found in either East Asia or Southeast Asia by 30-40K years ago. Archaeology suggests the arrivals were in Japan around that time too. There would have been time for a civilization to have evolved in the 20,000 years until the post-glacial ice melt and rising seas caused migrations to higher land and obliterated all evidence of coastal populations. We know from the writings of Spencer Wells (The Journey of Man); Stephen Oppenheimer (Out of Eden) and others that it is common knowledge or at least consensus that the Island Southeast Asia was once a huge land mass that held peoples who have older origins than in East Asia. As they fled the rising seas, many ended up settling mainland Southeast Asia, Taiwan, Korean and the Japanese archipelago. I think that since the Yonaguni structure likely shows a carved out-of-the-rock feature like Carpadoccia-type Uchisar Hill , rather than fitted stones of Angkor Wat-type civilizations … the scenario seems not at all unlikely.
Oops, that’s sphinxes!
YONA = YUNAN = ΙΩΝΑΣ = IONIAN = GREEK
GUNI = GONIA = ΓΩΝΙΑ = CORNER
YONA GUNI = GREEK CORNER.
IF ITS MAN MADE THEN THE ANCIENT GREEKS ARE ETYMOLOGICAL THERE…
Nice theory, but the timing makes it implausible. Greek-Bactrian influences upon Yunnan are way too late for Yonaguni which is thousands of years earlier. Time-frame for Greek-Bactria-Sogdiana influences is however closer to Kofun-through-Nara Japan. Some runic-like symbol was found, so perhaps runic, Cucuni-Tripolye or out of Sundaland-Island Southeast Asia would be most in line with genetic evidence.
As regards the carved, rather than fitted stone, nature of Yonaguni, there are other famous and undisputed examples, such as the magnificent cave temples in India (Ellora and many others). It can be and has been done, although I am in awe of the dedication of those who actually excavated all that stone for sacred purposes. And after 10,000 years or so of undersea battering, it doesn’t seem too strange that there isn’t much in the way of anything more than the largest, most important structure(s) left. Most monuments are like that, and often the only reason we can find evidence of roads, etc,, is that we are able to study the surrounding areas using an array of tools including aerial views, infrared, etc., which is pretty much impossible in this case. Places like Egypt, in addition, have been closely scrutinized internationally for far longer than this new site.
I must admit that I would really like Yonaguni to be man-made–the prospect is so exciting and would open up so many new possibilities–but it’s going to be difficult to prove one way or another. But new discoveries are being made every day, and you can’t rule anything out at this point. I still remember when most mainstream geologists laughed at the idea of “continental drift,” as it was known then, even though any 8-year-old could have pointed out the obvious puzzle-piece match-up of the South American and African coastlines. I hope I live to see the solution to this mystery.