Or just a natural formation?They are as mysterious as the European Atlantis: the submerged stones lying just below the waves splashing on the island of Yonaguni Jima could be the ruins of a Japanese Atlantis, an ancient unknown city sunk by a powerful earthquake about 2,000 years ago.
Its main defender is Masaaki Kimura, a marine geologist at the University of the Ryukyus in Japan, who has been investigating the structure for over 15 years.
"Each time I return to the dive boat, I am more convinced than ever that below me rest the remains of a 5,000-year-old city. The largest structure looks like a complicated, monolithic, stepped pyramid that rises from a depth of 25 meters [82 feet]," said Kimura.
But any hypothesis concerning the sunken city has its opponents.
"I'm not convinced that any of the major features or structures are manmade steps or terraces, but that they're all natural," said Robert Schoch, a professor of science and mathematics at Boston University who has dived at the place of the structure.
"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." he added.
"The Japanese government's Agency for Cultural Affairs nor the government of Okinawa Prefecture recognize the remains off Yonaguni as an important cultural property," said agency spokesperson Emiko Ishida.
"Neither of the government groups has carried out research or preservation work on the sites, instead leaving any such efforts to professors and other interested individuals." she added.
Yonaguni Jima is located on the southern tip of Ryukyu archipelago, just 75 mi (120 km) off Taiwan. The underwater formations were first discovered in 1986 and a nearby promontory was unofficially dubbed Iseki Hanto (Ruins Point). Because the site is unprotected, tourists and researchers can freely dive there.
Some researchers think the structures could come from Mu, a legendary Pacific civilization rumored to have been wiped out by the sea (does it sound familiar for the Atlantis fans?).
"I think it's very difficult to explain away their origin as being purely natural, because of the vast amount of evidence of man's influence on the structures," said Kimura.
"For example, I have identified quarry marks in the stone, rudimentary characters etched onto carved faces, and rocks sculpted into the likenesses of animals. The characters and animal monuments in the water, which I have been able to partially recover in my laboratory, suggest the culture comes from the Asian continent. One example I have described as an underwater sphinx resembles a Chinese or ancient Okinawan king." said Kimura.
"Whoever created the city, most of it apparently sank in one of the huge seismic events that this part of the Pacific Rim is famous for. The world's largest recorded tsunami struck Yonaguni Jima in April 1771 with an estimated height of more than 131 feet (40 meters), so such a fate might also have befallen the ancient civilization. I have identified ten structures off Yonaguni and a further five related structures off the main island of Okinawa. In total the ruins cover an area spanning 984 ft x 492 ft (300 m x 150 m)," he said.
The structures compass the remains of a castle, a triumphal arch, five temples and at least one big arena, all linked by roads and water channels and at least some protected by enormous retaining walls. Kimura thinks the ruins could be at least 5,000 years old, based on dating of stalactites encountered inside underwater caves sank at the same time with the "Japanese Atlantis".
"And structures similar to the ruins sitting on the nearby coast have yielded charcoal dated to 1,600 years ago-a possible indication of ancient human inhabitants," explained Kimura.
"Pottery and wood do not last on the bottom of the ocean, but we are interested in further research on a relief at the site that is apparently painted and resembles a cow. We want to determine the makeup of the paint. I would also like to carry out subsurface research." said Kimura.
"I've dived there as well and touched the pyramid. It's easy to tell that those relics were not caused by earthquakes." said Toru Ouchi, an associate professor of seismology at Kobe University.
But Schoch insists that holes in the rock, which Kimura attributes to posts supports, were made by underwater eddies.
"Lines of smaller holes were formed by marine creatures exploiting a seam in the rock. The first time I dived there, I knew it was not artificial. It's not as regular as many people claim, and the right angles and symmetry don't add up in many places." said Schoch.
"Many of the photos tend to give a perfect view of the site, making the lines look as regular as possible. Professor Kimura says he has seen some kind of writing or images, but they are just scratches on a rock that are natural. He interprets them as being manmade, but I don't know where he's coming from." he added.
Kimura is not undeterred by all this and now his researches have triggered the interest of the new governor of Okinawa Prefecture and officials from the United Nations Educational, Scientific, and Cultural Organization, now wishing for detailed investigations to be made at the site.
"The best way to get a definitive answer about their origins is to keep going back and collecting more evidence. If I'd not had a chance to see these structures for myself, I might be skeptical as well." said Kimura.
The myth of the European Atlantis, first mentioned by Plato 2400 years ago, is about a real ancient civilization wiped out by the sea. The Atlantic Ocean received its name from Atlantis, as many placed its location in the middle of this ocean. But recent proofs revealed that this civilization could have been located in the Crete Island, matching with the pre-Greek Minoan civilization.
3,500 years ago Minoans developed a complex civilization in the islands of the Eastern Mediterranean, while the rest of Europe was still in the Neolithic phase. There were building palaces, paved streets and sewers when Greek tribes lived in shelters. This pre-Greek population was not Indo-European, but rather related to the Basque or Caucasus ethnic groups.
By 1500 BC the people who created the myths of the Minotaur and the Labyrinth suddenly vanished, being destroyed by a giant tsunami. The Minoan civilization was made of seafarers and their towns were located mostly on the coast, exposed to tsunami. The ancient tsunami could have been as powerful as the Asian one that killed 250,000 people and was connected to the huge eruption of the Santorini volcano, 70 km north of Crete, up to 10 times more powerful than the Krakatoa's in 1883, volcanic stones even reaching the Egyptian shore of the Sinai peninsula while it was heard at over 3,000 miles (4,800 km) away.
The falling of Santorini's huge cone into the sea provoked the big wave, flooding many islands in the Aegean Sea. Probably the wave did not affect Knossos, the inland Minoan capital, but the massive ash falls could have ruined the crop, provoking famine. At the same date, Egyptians mention a huge invasion of the "People of the Sea", seafaring raiders that could chase famine away from the Crete Island. In Canaan, they mixed with local Hebrews, forming another civilization of seafarers, the Phoenicians. Etruscans' roots in Italy were also linked to this Atlantis collapse.