|Yonaguni island is the last island in the straggling Okinawa archipelago of south Japan. It emerged as a dive destination because of the large shoals of hammerhead sharks which arrive in February and March. But recently it has become one of the most important archaeological dive sites around, and finds itself at the centre of the debate on early human civilisation.
This is due to the discovery off its coastline of an underwater stone structure measuring 120m by 40m. As a natural phenomenon it would be spectacular, but if the structure was shaped by humans, as many scientists believe, it would date back 12,000 years to when that area was last above water, before the end of the last Ice Age. It would become the oldest man-made structure ever discovered, outdating the pyramids of Egypt by several thousand years and possibly signifying the existence of a previously unknown civilisation.
One renowned diver who has been to visit the site is Jacques Mayol, the pioneer of breath-hold diving, the inspiration behind the film The Big Blue, and the man who has an incredible affinity with whales and dolphins. He also knows a great deal about underwater archaeological sites.
When I went to Yonaguni, Mayol was there visiting his friend Kihachiro Aratake, the local dive guide who discovered the monument 13 years ago, with members of his Homo Delphinus team. To join the team, says Mayol, you have to be a good breath-hold diver, and above all not take yourself too seriously and have a playful mind.
But ours was to be a scuba dive.
Along with two members of the Homo Delphinus team and one of Aratakes staff to lead the way, I began to prepare myself mentally for what lay ahead. As our boat neared the location, I tried to imagine what the coastline might have looked like 12,000 years ago.
Minutes later we were ready to enter the water. The engines were cut, and over the side we went. My heart was pumping with anticipation. The water was incredibly blue, offering at least 45m visibility.
We entered a small tunnel through some rocks about 20m down. Standing before us, on the other side, were two huge monoliths that stretched straight upwards, appearing almost to reach the surface. The unbelievable clarity of the water made the sight seem almost unreal. I touched one of the columns, feeling its encrusted exterior as if I expected it to give me some kind of answer as to how it got there.
We followed the monument around to its southern face. From this side, steps rose from its base towards terraces at different levels. The pattern appeared to continue all the way to the summit. Holding on to a small cut in the rock, looking upwards as the strong currents pulled against my body, I was trying to imagine what possible meanings all these mysterious lines and plateaux held. Only the silhouettes of the many fish above reminded me that I was under water.
We swam away from the monolith over some coral and rock formations. Looking back from a distance, its size was overwhelming. The many terraces and steps appeared to have some type of architectural scheme, as if they had an underlying purpose. I knew I was seeing an amazing discovery, but at the same time I was left feeling puzzled.
Aratake, who looks like an 18th century pirate, with his hair pulled back in a pony tail, and a full beard, is a veteran of the sea with 30 years diving experience behind him. He accidentally discovered the monument when looking for new dive sites to put on a dive map for his business (he runs the South-west Yonaguni Dive Shop). He has logged numerous dives at the site, and knows its contours better than anyone. I have heard all kinds of theories from scientists, he says. What I believe is that this is some kind of ancient tomb.
One aspect of the monument which has some archaeologists doubting its connection with humans are several large steps. They appear much too high to be used by a person. Aratake, however, believes that they were not intended for that purpose.
He shows me a traditional-style tomb at one of Yonagunis ancient burial grounds. You see those two steps on each side of the entrance he asks as he points. They are very similar to what Ive seen on the monument. They are not used for stairs, but every tomb on Yonaguni has them.
I notice the resemblance right away. Perhaps they have some significant meaning that has been lost but can be connected to the monument.
Dr Masaaki Kimura, a professor and geologist from the University of the Ryukyus, has been studying the monument for the past seven years and is convinced that it shows signs of human modification. Others are more sceptical. They point out that there are many curious-looking rock formations on our Earth, but that they are completely natural. Furthermore, the Yonaguni site is composed of sandstone, which tends to break off in very straight lines and is easily eroded over time. Dr Koremasa Tsuji of the University of Guam believes the extensive tectonic plate movement in the area is responsible.
Mayol, however, has visited a number of underwater structures around the world over the years and brushes off theories that the monument is a freak of nature.
When I ask him if he believes that there might be a connection to the underwater sites that he studied in the Canary Islands and at Bimini Island, his eyes sparkle with enthusiasm. There was a race of humans called the Cro-Magnons. Some of the bones of Cro-Magnons have been found in the Canary Islands, where they are known locally as the Guanches. The average height of these humans was 2m. They had blond hair and blue eyes, and were extremely artistic. The theory is that they may have come from a lost continent - maybe Atlantis, explains Mayol excitedly as we stand on one of Yonagunis tall cliffs.
Before the continents drifted into their current formation, the islands of Okinawa, of which Yonaguni is one, would probably have formed a land bridge between mainland Japan and south-east Asia. This might have been a crossroads for overland migration and could even be a link to early trans-Pacific crossings.
This theory is supported by those scientists who believe that human migration to the Americas might not have been over the Bering Strait, but across the Pacific. Pottery has been discovered in Ecuador which bears similarities to pottery from the Jomon culture of Japan, which was active more than 10,000 years ago.
Yonaguni has definitely captured Mayols interest. I feel that I am in the middle of something so much bigger than I am. I got the same eerie feeling 20 years ago when I was diving regularly at prehistoric sites in the area of the Bahamas. I think that the monument at Yonaguni is partly man-made. It is absolutely obvious to me that it is not totally natural.
A true philosopher, Mayol also comments: We never try to understand the true nature of things. We are looking at this too much from the outside, and not enough from the inside. You see, true knowledge comes from within.
At the University of the Ryukyus, Dr Kimura tells me of the five points that lead him to believe the monument is modified by humans: The first is its whole shape. It resembles a pyramid or a castle. The second is that it has many small steps, about 20cm in height, that a person could have used as stairs.
The third point is that there are some parts that would have been very difficult to have been formed by wave action. The fourth is that there is something like a road with almost no rock fragments, showing it is not probable that it was made by natural forces. And the last point is the stone wall surrounding the road.
Kimuras theory is that the structure was used partly as a castle and partly as a temple. Looking at a scale-model put together by Kimura after he and his team surveyed the site, the resemblance to a 14th century Okinawan castle can be seen. Similarities to the Japanese castles of Shun and Nakagusku include stepped areas with flat, wide terraces; an arch, which could represent a gate, located on the west side of the monument; and deep, unexplainable holes located at another section.
At the monuments summit, there is an entrance leading downwards to what looks like some type of burial tomb. Kimura tells me it resembles those found in ancient Korea and Japan.
Kimura further explains that there are steps located on the northern side of the monument which faces the shoreline. Wave action could not have shaped the opposite side of the monument, he says.
It is hard to contest the argument that the geometric shape of the monument looks as if it has in some way been shaped by humans. There are also mysterious underwater structures located off the coast of some of Okinawas other islands. It could even be possible that other monuments as large as the one at Yonaguni are waiting to be discovered.
As the debate continues, Kimura is continuing to gather data. Unless artefacts to back up his theory are also found, it will be difficult to prove conclusively that the monument was shaped by humans.
Until any theory is proven, the best way to judge is to see for yourself.
A new edition of Jacques Mayols ground-breaking book Homo Delphinus (The Dolphin Within Man) is published this autumn. The book describes Mayols remarkable free-diving accomplishments, his experiences with dolphins and other marine species, and his views regarding the place of Man and other land-based mammals in the ocean world. Details from Underwater World Publications on 0181 943 4288, fax 0181 943 4312, e-mail firstname.lastname@example.org
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