France's new Stonehenge: Secrets of a neolithic time machine

Some months ago builders were clearing a piece of wasteland in southern Brittany when they struck an enormous hunk of granite. The developer was no historian but he knew instantly what the obstacle must be: the remains of a buried "menhir" or neolithic standing stone.

He ordered a bulldozer to shove the stone underground again before any passing busybody spotted it. He did not want the work on his six seaside bungalows to be halted for a prolonged archaeological dig.

Brittany, he probably reasoned, is crammed with old stones. At Carnac - the largest neolithic site in the world, just down the road - there is a linear forest of 3,000 menhirs in the space of four kilometres. Was that not enough ancient monuments to satisfy the historians, the tourists and the Ministry of Culture in Paris? Too late. A passing busy-body had noticed the unearthed menhir. Work on the bungalows was halted. An archaeological dig was ordered.

As a result, our knowledge of early human history may be transformed - or at least deeply enriched. Preliminary exploration of the site has just been completed. One of France's foremost experts on neolithic times calls the results a "miracle". Other experts speak of a "time machine".

The Ministry of Culture is in the process of designating the whole area - 10 times larger than the 3,000 square metre preliminary dig - as a place of overwhelming historical importance. In other words, the six new bungalows at Kerdruelland, near Belz, in Morbihan, will never be built.

To neolithic experts, the name Kerdruelland may yet come to have something of the same significance as Stonehenge or Carnac or Newgrange in Co. Meath. The site may provide - like a kind of modern-day Rosetta Stone- some of the clues to unlock the code of one of the most important but puzzling chapters in human development.

The middle and late-neolithic (or Stone Age) and early Bronze Age in western Europe - roughly from 4000 BC to 1500 BC - was a period of rapid and revolutionary advance. European man made pottery and tamed animals for the first time. He turned from hunting to agriculture. He emerged from caves and built houses. He progressed from cave-painting to the building of elaborate stone and earth tombs and - many years before the Egyptian pyramids - to the construction of carefully plotted and painstakingly laboured alignments and circles of standing stones. There are 3,000 of them in Britain, Ireland and Brittany alone. They are also scattered from Denmark to Portugal and southern Italy. Much has been discovered about the period in the past 50 years. Much remains utterly mysterious.

Archaeologists working on the Kerdruelland site over the past nine months have discovered not one but 60 "lost" menhirs. They believe that they were erected - and then destroyed - during the "middle period" of the standing stones era in western Europe, in around 2500 BC. (This was about the same time that the main ring at Stonehenge was constructed, possibly by invaders from Brittany).

Because the Kerdruelland menhirs have been preserved in mud and silt for 4,500 years, they should offer important new information on how such alignments were created and why. At the well-known sites, such as Carnac and Stonehenge, some of the stones have been moved or propped up or stolen or added over the centuries. Here the stones, up to 2m long, lie just as they did after they were felled four-and-half millennia ago.

At neolithic sites elsewhere, the soil of the period has been eroded by the ravages of time and man. At Kerdruelland, the neolithic sub-soil - the soil on which the stones were erected - has been preserved intact. This offers a cornucopia of possible new archaeological finds. Already, a brief dig has yielded a rich harvest of flint tools and shards of pottery.

Just as importantly, the preservation of the neolithic sub-soil will help the experts to discover traces of the original earthworks and study the methods of assembling and positioning the menhirs.

The fact that the stones were erected, and then deliberately toppled, at roughly the same time, is also an important discovery. It offers new evidence that the neolithic was a period of social and religious upheavals, revolutions and wars. In other words, the neolithic may have been "megalithic" - obsessed with whacking great stones - but it was not socially or culturally monolithic. Ancient man was as fractious and destructive as modern man.

Professor Jean-Paul Demoule is president of the French agency which undertakes urgent archaeological digs on threatened sites - L'Institut national de recherches archéologiques préventives (Inrap) - which undertook the preliminary dig at Kerdruelland. He is also one of France's, and the world's, leading experts on the neolithic era: "This site is, historically and archaeologically speaking, a miracle," he told The Independent. "It is a great paradox. Precisely because it was destroyed, it has been preserved: like the wreck of an ancient ship beneath the ocean."

"The great neolithic sites like Stonehenge, such as Carnac, have come down to us, still standing, through the millennia and we can look at them as we imagine that they always were. But we cannot be sure that they were exactly that way and - most importantly - the soil in which they were planted has gone. If you dig at Stonehenge or Carnac today, you are mostly digging into the soil of previous ages, before the stones were placed there. Here, we are digging into the neolithic soil itself, the soil on which the erectors, and destroyers, of the stones once stood and lived."

Stephan Hinguant, 43, the chief archaeologist on the site, said: "This is as a truly astonishing find, a time machine. We have only explored a small part of it, and very rapidly, but we have found enough to know that there is a treasury of information here which will take several years to uncover fully.

"We have found 60 stones, some complete, some broken, but we believe that there must be many more in the surrounding site. Once we have established where the stones originally stood, we will be able to draw conclusions, based on scientific fact, not on guesswork. The artefacts we find in the soil and evidence of how the stones were placed upright could make enormous contributions to our understanding of neolithic culture..."

Until the archaeological work resumes, probably next year, the experts are unwilling to say whether the stones originally formed lines, or a circle, or, typically for Brittany, a horse-shoe.

Kerdruelland today is a banal stretch of seaside suburbia. Here and there a huge lump of rough, yellow-orange coloured granite pokes through the plastic protecting the site from summer storms. To have some idea of how Kerdruelland must have looked 4,000 years ago, you do not have to go far. Eight miles to the east are the three vast alignments of stones, and their associated "cromlechs", or large stone circles, near the village of Carnac.

The stones are large and small, straight and jagged, mostly erected just as they were found. They stretch into the distance, like rotting giants' teeth, offering little clue as to why they were strung out over such a large area.

Neolithic historians believe that the original rows of stones at Carnac were a kind of ceremonial avenue, leading to a large enclosure of stones or "cromlechs", where ritual gatherings took place. The first stones may have been erected around 3500 BC - 1,000 years before those at Kerdruelland.

In his seminal, recently republished work The Stone circles of Britain, Ireland and Brittany (Yale University Press), the British neolithic expert, Aubrey Burl, suggests that the original, simple avenues at Carnac were augmented and muddled until Roman times, and maybe even more recently, by an annoying local habit of adding a couple of stones each year.

Hence, the frustrations of neolithic archaeologists and historians. Professor Burl also refers despairingly to a stone circle at Hampton Down in Dorset. A photograph from 1908 shows 16 pillars. By 1964, there was a ring of 28. Later excavation suggested that only eight were genuine. But which ones? Professor Burl also complains that our understanding of standing stones has been warped by Stonehenge, which is extraordinary but atypical.

Most circles use stones which were lying around near by. Rock was rarely quarried or carried very far. The "sarsen" stones in the main ring at Stonehenge are an exception. They came from 20 miles away. It is estimated that it would have taken 200 men to drag each slab 100m a day. The ambitious "lintels" joining the sarsen stones at Stonehenge do not occur in any other neolithic monument.

Mr Burl insists that the Wiltshire masterpiece is a "unique example of megalithic madness". Most other stone circles are more modest and could have been put together little by little, and changed over the centuries, by small clans or family groups.

But why build stone circles or alignments at all? In a book published last year, Inside the Neolithic Mind (Thames and Hudson), David Lewis-Williams and David Pearce try to psychoanalyse the late stone age. They bring together archaeological evidence from the Middle East, western Europe and modern scientific studies of the chemistry of the brain. The results are sometimes far fetched but the book traces a convincing progression from cave art to stone circles.

As man emerged from the caves and forests to cultivate open ground, he replicated the old, sacred caves by building cave-like tombs. These were made of groups of stones, covered with soil. At some point, in around 4000 to 3500 BC, mankind emerged further into the light. The pattern of stones within the tombs was expanded and uncovered to form ceremonial stone circles.

What happened inside such enclosures has excited fevered speculation for centuries. Human sacrifice? Elaborate astronomical observations? Sexual and drunken orgies? Ceremonies at the winter and summer solstices to encourage the healthy growth of crops? Professor Burl suggests that, far from being elaborate astronomical observatories, most stone-circles are shaped by local topography. They do often, however, have alignments with summer and winter solstices and the movements of the Moon. Professor Burl's best guess on their purpose is a mixture of propitiation of the crop gods and sexual and alcoholic-psychedelic orgies. There is much archaeological evidence that the late Stone Age was also a stoned aged.

Professor Jean-Paul Demoule says that it is clear that the neolithic period was "not a calm river of slow evolution" but a "period of violent upheavals, wars and revolutions" as cultural and religious groups fought and colonised one another. In no other site before the discovery of Kerdruelland, however, have archaeologists found a large group of standing stones which were toppled but not re-used.

For this reason alone, the site offers the prospect of startling new discoveries and insights in the years ahead. It is a pity about the bungalows. However, southern Brittany, though crammed with ancient monuments, is not short of a few bungalows.