Farmers first reached Orkney on boats that took them across the narrow but treacherously dangerous Pentland Firth from mainland Scotland. These were the people of the New Stone Age, and they brought cattle, pigs and sheep with them, as well as grain to plant and ploughs to till the land. The few hunter-gatherers already living on Orkney were replaced and farmsteads were established across the archipelago. These early farmers were clearly successful, though life would still have been precarious, with hunting providing precious supplies of extra protein. At the village of Knap o'Howar on Papay the bones of domesticated cattle, sheep and pigs have been found alongside those of wild deer, whales and seals, for example, while analysis of human bones from the period suggest that few people reached the age of 50. Those who survived childhood usually died in their 30s.
Discarded stone tools and shards of elegant pottery also indicate that the early Orcadians were developing an increasingly sophisticated society. Over the centuries, their small farming communities coalesced into larger tribal units, possibly with an elite ruling class, and they began to construct bigger and bigger monuments. These sites included the 5,000-year-old village of Skara Brae; the giant chambered grave of Maeshowe, a Stone Age mausoleum whose internal walls were later carved with runes by Vikings; and the Stones of Stenness and the Ring of Brodgar, two huge neighbouring circles of standing stones. These are some of the finest Neolithic monuments in the world, and in 1999 they were given World Heritage status by Unesco, an act that led directly to the discovery of the Ness of Brodgar.
"Being given World Heritage status meant we had to think about the land surrounding the sites," says Card. "We decided to carry out geophysical surveys to see what else might be found there." Such surveys involve the use of magnetometers and ground-penetrating radar to pinpoint manmade artefacts hidden underground. And the first place selected by Card for this electromagnetic investigation was the Ness of Brodgar.
The ridge was assumed to be natural. However, Card's magnetometers showed that it was entirely manmade and bristled with features that included lines of walls, concentric pathways and outlines of large buildings. "The density of these features stunned us," says Card. At first, given its size, the team assumed they had stumbled on a general site that had been in continuous use for some time, providing shelter for people for most of Orkney's history, from prehistoric to medieval times. "No other interpretation seemed to fit the observations," adds Card. But once more the Ness of Brodgar would confound expectations.
Test pits, a metre square across, were drilled in lines across the ridge and revealed elaborate walls, slabs of carefully carved rock, and pieces of pottery. None came from the Bronze Age, however, nor from the Viking era or medieval times. Dozens of pits were dug over the ridge, an area the size of five football pitches, and every one revealed items with a Neolithic background.
Then the digging began in earnest and quickly revealed the remains of buildings of startling sophistication. Carefully made pathways surrounded walls some of them several metres high that had been constructed with patience and precision.
"It was absolutely stunning," says Colin Richards. "The walls were dead straight. Little slithers of stones had even been slipped between the main slabs to keep the facing perfect. This quality of workmanship would not be seen again on Orkney for thousands of years."
Slowly the shape and dimensions of the Ness of Brodgar site revealed themselves. Two great walls, several metres high, had been built straight across the ridge. There was no way you could pass along the Ness without going through the complex. Within those walls a series of temples had been built, many on top of older ones. "The place seems to have been in use for a thousand years, with building going on all the time," says Card.
More than a dozen of these temples have already been uncovered though only about 10% of the site has been fully excavated so far.
"We have never seen anything like this before," says York University archaeologist Professor Mark Edmonds. "The density of the archaeology, the scale of the buildings and the skill that was used to construct them are simply phenomenal. There are very few dry-stone walls on Orkney today that could match the ones we have uncovered here. Yet they are more than 5,000 years old in places, still standing a couple of metres high. This was a place that was meant to impress and it still does."
But it is not just the dimensions that have surprised and delighted archaeologists. Two years ago, their excavations revealed that haematite-based pigments had been used to paint external walls another transformation in our thinking about the Stone Age. "We see Neolithic remains after they have been bleached out and eroded," says Edmonds. "However, it is now clear from Brodgar that buildings could have been perfectly cheerful and colourful."
The men and women who built at the Ness also used red and yellow sandstone to enliven their constructions. (More than 3,000 years later, their successors used the same materials when building St Magnus' Cathedral in Kirkwall.) But what was the purpose of their construction work and why put it in the Ness of Brodgar? Of the two questions, the latter is the easier to answer for the Brodgar headland is clearly special. "When you stand here, you find yourself in a glorious landscape," says Card. "You are in the middle of a natural amphitheatre created by the hills around you."
The surrounding hills are relatively low, and a great dome of sky hangs over Brodgar, perfect for watching the setting and rising of the sun, moon and other celestial objects. (Card believes the weather on Orkney may have been warmer and clearer 4,000 to 5,000 years ago.) Cosmology would have been critical to society then, he argues, helping farmers predict the seasons a point supported by scientists such as the late Alexander Thom, who believed that the Ring of Brodgar was an observatory designed for studying the movement of the moon.
These outposts of Neolithic astronomy, although impressive, were nevertheless peripheral, says Richards. The temple complex at the Ness of Brodgar was built to be the most important construction on the island. "The stones of Stenness, the Ring of Brodgar and the other features of the landscape were really just adjuncts to that great edifice," he says. Or as another archaeologist put it: "By comparison, everything else in the area looks like a shanty town."
For a farming community of a few thousand people to create such edifices suggests that the Ness of Brodgar was of profound importance. Yet its purpose remains elusive. The ritual purification of the dead by fire may be involved, suggests Card. As he points out, several of the temples at Brodgar have hearths, though this was clearly not a domestic dwelling. In addition, archeologists have found that many of the stone mace heads (hard, polished, holed stones) that litter the site had been broken in two in exactly the same place. "We have found evidence of this at other sites," says Richards. "It may be that relatives broke them in two at a funeral, leaving one part with the dead and one with family as a memorial to the dead. This was a place concerned with death and the deceased, I believe."
Equally puzzling was the fate of the complex. Around 2,300BC, roughly a thousand years after construction began there, the place was abruptly abandoned. Radiocarbon dating of animal bones suggests that a huge feast ceremony was held, with more than 600 cattle slaughtered, after which the site appears to have been decommissioned. Perhaps a transfer of power took place or a new religion replaced the old one. Whatever the reason, the great temple complex on which Orcadians had lavished almost a millennium's effort was abandoned and forgotten for the next 4,000 years.
For more information or to donate to the dig, go to orkneyarchaeologysociety.org.uk
http://www.guardian.co.uk/science/2012/oct/06/orkney-temple-centre-ancient-britain?newsfeed=true