4.0 Methodology
4.1 Offshore explorations
Two boats were chartered for explorations off Yonaguni waters from 2 September 2000 to 8 September 2000. The Remotely Operated Vehicle (ROV) was deployed simultaneously with side-scan sonar and echosounder. The ROV was operated with generator power supply. The system was operated in waters between 40 to 80 metres depth around Yonaguni. The survey revealed a rock-cut channel about I m wide and more than 20 m long at 2 sea mounts. The ROV observations were confirmed by diving.
5.0 Results
5.1 Terraceda structure and canal
A large terraced structure of about 250 metres long and 25 metres height was studied south of the Arakawabana headland. Known locally as Iseki Point, the terraced structure is bound to the northern side of an elongated, approximately east-west trending structure, designated by Professor Masaaki Kimura, University of the Ryukyus, as an approach road. But our observation of the proposed road-like structure suggests that it is more likely to be a canal. The overall width of the terraced structure is around 100 m. From each of the terraces, a staircase leads downwards to the canal (road?).
The length of the canal appears to be more than 250 m, while the canal has a width of 25 m. The purpose or utility of this canal structure is intriguing. Our observation all along the canal indicates that the western end of the structure begins underwater opening away from the terraced structure into the open sea. The width, height and terraced northern side of the canal force us to suggest that the canal structure might have served as a channel for small boats communicating with the Arakawabana headland. The southern natural outcrop wall probably had provided a buffer wall for strong open sea waves. This interpretation appears quite reasonable because the height of the southern wall of natural outcrop and the northern terraced wall are nearly same. The terraces and attached staircases might have been used for handling, loading and unloading boats sailing through the channel. Thus it appears in all probability that the terraced structure and canal might have served as a jetty before submergence to present depth.
5.2 Monolith human head
A large monolith that looks like a human head with two eyes and a mouth was studied at Tatigami Iwa Point. A human-cut large platform in the same monolith extends outwards at the base of the head. An approach way leads to this platform from the shore-side.
The surrounding basal platform is quite large (about 2500 m2), and could easily have accommodated more than two thousand persons sitting. The human head and associated platform with an approach road are suggestive of an area of worship or community gatherings.
5.3 Underwater cave area
Diving operations revealed caves at 8 to 10 m water depth at ‘Palace’ area. The entry to these caves was possible only through the large 1 metre radius holes on the cave roof. Inside the cave a boulder about 1 metre diameter engraved with carvings was observed. About 100 m towards the eastern side of the caves more rock engravings were noticed on the bedrock. These rock engravings are believed to be man-made.
Once upon a time these caves were probably on the land and were later submerged. The rock engravings inside the cave and on the bedrock were probably carved out by means of a tool of some sort. However, it is very difficult to say that these are rock art of this or that period, or a script.
5.4 Megaliths Point
Diving operations revealed two big rectangular blocks measuring 6 metres in height, about 2.5 metres in width (both) and 4.9 metres thickness which have been located towards the western side of Iseki Point … These rectangular blocks are designated by Japanese workers as megaliths. These blocks have been located in between two natural rock outcrops. The approach way to these megaliths is through a tunnel measuring about 3 m long, 1 m high and 1 m width.
The shape, size and positioning of these megaliths suggest that they are man-made. It is believed that the people of Japan’s extremely ancient Jomon culture used to worship stones, rocks (Hancock, personal communication, 2000). In light of this practice, it may be worthwhile to suggest that these megaliths might have been used as objects of worship. However, a thorough investigation in this regard is necessary before assigning a definite purpose to these megaliths.
6.0 Conclusion
The terraced structures with a canal are undoubtedly man-made, built by cutting an existing huge monolithic outcrop. The rectangular terraced structure and canal probably might have served as a jetty for handling, loading/unloading small boats before its submergence to present depth.
The monolith rock-cut human head and associated platform might have served as an area of worshipping or community gatherings.
The score so far
By my count so far I have one marine archaeologist, Sundaresh, who is convinced that the Yonaguni structures are ‘undoubtedly man-made’, and who represents 100 per cent of all the archaeologists who have ever dived there up to the time of writing. I also have one marine geologist, Masaaki Kimura, who believes the same thing, a second geologist, Robert Schoch, who is undecided, and a third, Wolf Wichmann, who is convinced that they are natural.
I decided when I got the opportunity that I should try to dive at Yonaguni with Wichmann and see if I could change his mind. To this end, a few months after the Der Spiegel article appeared, I made the following statement on my website:
I would like to offer a challenge to Wolf Wichmann … Let us agree a mutually convenient time to do, say, twenty dives together at Yonaguni over a period of about a week. I will show you the structures as I have come to know them, and give you every reason … why I think that the monuments must have been worked on by human beings. You will do your best to persuade me otherwise. At the end of the week let’s see if either side has had a change of mind.13
‘Japanese scientists cannot dive …’
In March 2001, on a mini-expedition funded by Channel 4 Television, Wichmann took up my challenge. A small, wiry, dark-haired, unpretentious man, I liked him the moment I met him, and continued to do so throughout the week that we spent diving in Japan and arguing, in a mood of amiable disagreement, about what we were seeing underwater.
Predictably we did not reach a consensus: Wolf left Yonaguni still holding most of the opinions with which he had arrived, and so did I. But I think that we each gave the other some worthy points to ponder. I know that I benefited from what amounted to a very useful field seminar on the natural history of submerged rock and began to understand clearly for the first time exactly how and why a geologist might conclude that the Yonaguni underwater structures are entirely natural – or at any rate (to sum up Wolf’s position more accurately) that they all could have been formed by known natural forces with no necessity for human intervention.
Before going on to Yonaguni, Wolf and I paid a visit to Professor Masaaki Kimura at his office in the University of the Ryukyus. I started the ball rolling with a general question for Professor Kimura concerning the age of the structure:
GH: People can argue for the next five centuries about whether what we see underwater at Yonaguni is man-made or artificial. But one thing which we can hopefully get clear is how old it is … when it was submerged? So the first question I want to ask you is what is your view of the age of this structure? The last time that it was above water?
Kimura: This construction has been submerged since 6000 years ago, because the coralline algae attaching to the wall of this structure shows 6000 years.
GH: And those coralline algae, because they’re organic, you’ve been able to carbon-date them?
Kimura: Yes, carbon 14.
GH: Right. So that tells us the age of that biological item … it’s 6000 years old and it’s attached to a stone structure which, therefore, must be older than that.
Kimura: It must be older, and so in general 6000 years ago the sea-level at that time [was lower] … So if this was made by men, this must be when this area was land … it’s about 9000 or 10,000 years ago.
GH: 9000 or 10,000 years ago? So – again to clarify, because I need to ge
t this straight – you’re saying that 9000 or 10,000 years ago, the whole area was above water and the date of submergence would be about 6000 years ago?
Kimura: Before 6000 years ago.
GH: This is the problem with carbon 14, isn’t it? It dates the organism, not the structure. So then you can only say that the structure is older than that, but how much older is not sure. How much work have you done on sea-level change as a dating guide? And how big a factor is the possibility of sudden, maybe recent land subsidence as a result of earthquake?
Kimura: Yes, I’m looking for such evidence, that is, geological evidence, but there is no evidence of movement. If this area had subsided by movement it would be due to earthquakes and faulting, but there is no active fault near by, the fringing coast is continuous, and between the beach and Iseki Point, there is no discontinuity or fault.
Wolf: I see.
GH: That makes things fairly clear, then. It leaves us with the sea-level issue on its own to base a date on, without complicating factors, which is great. At least we can be clear on one thing.
Wolf: I think that questions for sea-level rise are very fairly proved by scientific evidence here in the area. I mean, they’re experts in their field.
GH: So you’d have no problem with the 9000 year date?
Wolf: No, no … not at all. No, the question was, or is still, is it and, if yes, to what extent is it made by man or overworked by man? This is the question.
GH: Well hopefully we’ll get a chance to investigate that when we go to Yonaguni.
Kimura: We need to research much more.
Wolf: Yes.
GH (speaking to Prof. Kimura): I mean you’re practically the only person who’s done – you and your team here – have done continuous research for some years. But almost nobody else is working on it, I think, at the moment?
Kimura: Japanese scientists cannot dive.
‘A very fine, a very nice thing …’
Throughout our discussion Professor Kimura strongly maintained his commitment to the man-made character of Yonaguni’s underwater monuments – not simply on the basis of his technical findings, cited earlier, which I need not repeat here, but also, and I found persuasively, because: ‘This kind of topography – if this has been made by nature it is very difficult to explain the shape.’
Wolf’s riposte was immediate: ‘So what I would say to that formation is that I’ve seen many natural formations, especially coastlines, being worked out by waves and wind, especially with the help of weapons, erosive weapons – sand and so on … Seeing with the eye of a geologist or a morphologist it is, OK, a very fine, a very nice thing, but possibly made by nature.’
I asked Wolf whether in fact he had ever seen anything like the Yonaguni ‘formation’ anywhere else in the world.
‘Not in that exact combination,’ he replied. ‘This is what is surprising me; it’s a very strong, compressed combination of the different shapes and the different figures you can find naturally in the world somewhere.’
‘But you don’t usually find them in combination like this?’
‘No, I haven’t seen that. So that is a marvel. It is a very beautiful formation.’
‘Or the work of human beings?’ I prompted.
‘Or of that. So that’s what we’re here for.’
The ramp
On our first dive at Yonaguni I took Wolf to a very curious structure that I had discovered in late June 1999. It stands in 18 metres of water 100 metres to the west of the terraces of the main monument. When it was above sea-level 8000 or 10,000 years ago I suggest that it was originally a natural and untouched rocky knoll rising about 6 metres above ground level. A curving sloped ramp 3 metres wide was then cut into the side of the knoll and a retaining wall to the full height of the original mound was left in place enclosing and protecting the outside edge of the ramp.
I led Wolf to the base of the ramp, and as we swam up it I pointed out how the outer curve of the inner wall – which rises 2 metres above the floor of the ramp and is formed by the body of the mound – is precisely matched by the inner curve of the outer wall, which also rises to a height of 2 metres above the ramp floor, so that both walls run perfectly parallel. Moreover, when we swam up and over the rim of the outer wall we could see that its own outer curve again exactly matches the curves within and that it drops sheer to the sea-bed – as it should if it is indeed a purposeful wall and not simply a natural structure.
I showed Wolf that the ramp floor itself, though battered and damaged in places, must originally have had a smooth, flat surface. I also showed him what I believe may have been the function of the ramp. As one continues to follow it round it leads to a platform offering an impressive side-on view of the two huge parallel megaliths, tucked into an alcove in the north-west corner of the main monument, that constitute a spectacular landmark in the Yonaguni ‘underworld’. Later we discussed what we’d seen:
GH: OK, Wolf, the first dive we did I brought you to a structure [attempts to draw ramp structure on notepad) – I’m sorry, I’m hopeless at drawing …
Wolf: Me too … (peers at drawing) OK, so I recognize it.
GH: Hey, you’re a geologist, you should be able to draw. [Continues drawing.) And here is a rather nice wall going round on both sides, and in the middle is a bedrock channel or ramp. And it rises from here around to this corner and, in fact, if we follow it all the way round it leads us to a view of the megaliths. Now this wall is not a bank. It is a wall. It’s actually about half a metre wide. And it’s high … more than 2 metres high …
Wolf: Round about.
GH: … Above this … above this ramp, whatever you want to call it. So I simply cannot understand the combination of clean bedrock here (indicates the ramp floor), admittedly very eroded and damaged, but clean bedrock here, and these heavily overgrown walls, which are definitely wall-like in appearance and rather high in the sense that they have an outer and an inner edge, and the curve of the outer edge matches the curve of the inner edge; and the same on the other wall.
To my surprise Wolf immediately admitted that this rather innocuous-looking and only recently discovered structure, which he had not been shown on his previous visit, was a ‘real challenge’. He was later to describe it as ‘the most impressive thing’ he had seen at Yonaguni:
The most impressive thing for me was the wall, the wall which is totally covered by living organisms nowadays, which should be removed to have a look at the structure of that wall, which can also be explained as having been done possibly by nature, but to get it sure we have to do deep research on that.14
Nevertheless Wolf would not have been Wolf if he had not at least attempted to come up with a calm, level-headed and unsensational geological explanation for the problem. He therefore drew my attention now to a place on land on Yonaguni called Sananudai that we had taken a look at the day before where he had shown me wall-like formations – admittedly only half a metre high – that had been formed entirely naturally:
Wolf: OK, this is a real challenge to solve. But if you remember, the day before we have been on a platform on land – I forgot the name of the point –
GH: Sananudai?
Wolf: Right, correct. And by chance we went further down near the sea, and I showed you these encrustation patterns and maybe you remember that I …
GH: I remember distinctly; you told me that a hard patina formed on the outside of the rock and that the water softened out the inside, leaving a wall-like shape in place.
Wolf: Correct. And on the other side the relatively soft sandstone had already begun to be removed. So … and I told you that this could be a possible way that a wall can be made by nature … OK, it’s a theory.
GH: It’s a theory. I mean, what I saw at Sananudai was actually no curved walls running in parallel with each other, but rather straight, and they were about half a metre high.
Wolf: They were at the beginning stage. Right. And if you had a look closer down, you would have seen that there was a little
curving, not as clear as this, I have to admit. But I mean, that was really the beginning stage so we don’t know.
GH: So would you want to explain those walls [on either side of the ramp] that way, as a hard patina which was preserved, and the soft part was cut out?
Wolf: At first, and then subsequently overgrown by organisms as we saw. But to get clear what that really is, so I underline repeatedly, it is a challenge, and this is the first and only explanation I have for this. But to really get clear of this fact, we should have to remove the encrustation on one spot, or just from top to the bottom … This is the only way to find out of what material this wall consists – there’s no other way; or to drill a hole through … We are obliged to find out what these walls are made of. Are they made of single patterns like stones or something?
GH: Well, see, I don’t … I very much doubt if the walls will turn out to be made of blocks. I think they’ll turn out to be cut. I think we’re looking at megalithic culture which cut rock. I think they cut down into the living rock, and they created the walls by cutting, and then later on the encrustation came and grew on top of the walls. That’s my theory.