THE FIRST comprehensive survey of the world's largest series of prehistoric stone monuments has just been completed by a leading British archaeologist.
Dr Aubrey Burl has spent 20 years travelling more than 20,000 miles throughout Britain, Ireland and Brittany, in search of ancient stone circles and similar monuments, and has succeeded in tracking down some 2,200.
His detailed analysis of their design and geographical distribution is now shedding important new light on a 2,300-year-long period of British prehistory. Differing widely in size, the sites fall into four main categories - stone circles, stone avenues, stone rows and multiple stone rows.
The site with the most stones - a multiple row complex at Kerzerho in Brittany - consists of 1,129 standing stones, while the largest site in terms of area is the 28-acre great stone circle at Avebury, in Wiltshire.
The longest row, running across Stall Moor on Dartmoor, is two- and-a-half miles long and has 2,000 stones; while the largest single stone (now broken into five pieces) - near Locmariaquer in Brittany - was originally 75ft high and weighed more than 300 tons. In Ireland the most complicated complex, at Beaghmore, Co Tyrone, has seven circles and eight rows.
The 2,200 sites studied by Dr Burl consist of a grand total of around 30,000 stones. His comparative analysis of all these British, Irish and Breton prehistoric monuments has revealed the way in which architectural and religious traditions developed and spread between approximately 3300BC and 1000BC (the late Neolithic and Bronze Age). In particular, his in- depth study of stone avenues and rows - just published in book form by Yale University Press - shows, for the first time, how those monuments first developed in very rudimentary form in the Lake District, and then spread south to Wessex, Devon and Cornwall, and finally to south-west Ireland.
Northern Ireland was directly influenced by Lake District standing stone "architecture", while western Scotland seems to have derived its inspiration from Brittany. This suggests not only that ideas travelled long distances, but that the sea was probably even more important as a cultural highway than scholars have hitherto believed. Dr Burl's study also shows how prehistoric architectural fashion developed over time.
Initially, the stone avenues start off as two- or four-stone extensions to stone circle entrances. Then, after many generations, they were gradually extended to become avenues, slowly increasing in length. After around 2000BC, some avenues and their simpler derivatives, stone rows, were being built on their own, no longer in association with pre-existing stone circles.
In some cases, stone rows were constantly added to, with new, roughly parallel, rows being erected. The most complicated in Britain, in Mid-Clyth, Caithness, has 23 lines of stones (some 300 in total), while at Kerlescan in Brittany there are 13, with more than 500 stones in total.
Finally, as the standing-stone monument tradition began to falter, both rows and avenues became less complicated and less impressive, ending up in the late second millenium BC as simple pairs of stones.
Dr Burl has also carried out detailed calculations to determine whether any of the avenues and rows are aligned astronomically. His research now shows that, whereas stone circles show a mixture of solar and lunar alignments, detached stone avenues and rows built after around 2000BC are almost exclusively lunar in their orientation.
Together with the architectural changes, the spread of exclusively lunar avenue and row alignments will lead archaeologists to speculate as to the causes of these trends. Perhaps wider demographic, military or social developments lay behind these religious changes. Stone circles, avenues and rows can normally only be built in areas where suitable stone is easily available. …