(Originally published: July 4, 2008)
The Ring of Brodgar is one of the largest Neolithic stone circles in Britain. Yet we know surprisingly little about it – in particular its age.
This summer, for the first time in 35 years, archaeologists are carrying out excavations at the ring, hoping to answer a number of long-standing questions. . .
The stone circle is undoubtedly one of Orkney’s best-known ancient monuments and stands on the Ness of Brodgar – a low-lying isthmus that separates the lochs of Harray and Stenness, centrally placed within the large natural bowl of Orkney’s West Mainland.
As a monument, the Ring of Brodgar is not alone. Together with the Stones of Stenness, a much smaller stone circle set within an enclosing ditch, it forms part of a monumental group, which also includes Maeshowe and a number of other archaeological features.
In contrast to the Brodgar ring, however, most of the other monuments have been examined by excavation, for instance Maeshowe in 1956 and the Stones of Stenness in 1976. Although the results have been variable, especially with regard chronological sequences, these interventions allowed detailed and inclusive interpretative accounts to be created.
However, when it comes to the Ring of Brodgar we still know very little about this amazing site. Instead interpretation has been constructed on the basis of the characteristics of other sites.
So what do we actually know?
The monument is composed of a circular ditch and internal stone circle. The enclosing ditch is c.123m in diameter, with two opposed causeway entrances in the north-west and south-east. The internal stone circle has a diameter of c.103m.
And that’s about it.
Although an excavation to date the ring took place 35 years ago, the attempt failed, primarily due to the limitations of available dating techniques. As a result we still don’t actually know how old the stone circle is.
The second example of a lack of knowledge, and its effects, concerns the architecture of the Ring of Brodgar.
It is common to come across references to the similarities between the Stones of Stenness and Ring of Brodgar and frequently they are treated as if they were almost equivalent constructions. Actually, the two sites are architecturally very different and this difference is not merely a question of scale.
Both the Ring of Brodgar and Stones of Stenness have been identified as henge monuments since the monumental type was initially identified. However, the necessary combination of an external bank and an internal ditch of the “classic” henge monument, while possibly present at the Stones of Stenness, clearly never existed at the Ring of Brodgar.
Today, there is absolutely no hint of an external bank.
Had there once been an external bank, it would have been a very prominent and substantial feature, being mainly composed of quarried bedrock. The absence of any visible trace of such a bank prompted a trench being excavated in 1973. Despite a greater depth of topsoil, no evidence of a bank was discovered.
The lack of an external bank removes the Ring of Brodgar from the typological definition of a henge monument. No longer can the earthwork be discussed by recourse to other “henge monuments”. Equally, there are some subtle aspects of architecture, which have been glossed over.
In a number of plans of the monument, (e.g. Renfrew 1979: Fig. 39; RCAMS 1946: Fig 374), the two causeways across the ditch, to the north-west and south-east, are shown as being fairly uniform in size. In reality the two causeways are very dissimilar with the south-eastern causeway considerably narrower.
The difference between the two causeways and the absence of an external bank are just two features of the earthwork, which conspire to highlight the unusual nature of the Ring of Brodgar.
There are similar problems concerning the assumptions attached to the Ring of Brodgar.
Generally, the stone circle is stated to have originally been composed of 60 monoliths But this has never been proven archaeologically.
This year, a geophysical survey will provide important information regarding the position of stone sockets and original number of stones within the circle. In addition, a re-examination of the ditch sections, particularly the primary infill of material from the interior, will give additional information regarding the presence of an internal “platform”, as opposed to an external bank at the Ring of Brodgar.
An alternative hypothesis is the stony infill material in Trench C is a single discrete deposit and relates to the spoil from stone socket digging. Careful re-examination of the ditch stratigraphy over a length of ditch extended slightly beyond Renfrew’s excavation may resolve this issue.
The month-long programme of investigations, which start on July 7, will be undertaken by a 15-strong team of archaeologists and scientists from Orkney College, the University of The Highlands and Islands, University of Manchester, Stirling University and The Scottish Universities Environment Research Centre (SUERC).
Their aim will be to gather information which will enable a much better understanding of the nature of the iconic site.
It is hoped that the new investigations to retrieve datable material and examine archaeological and palaeo-environmental material, will reveal facts about the Ring of Brodgar and help its mysteries to be unravelled.
The 2008 project will involve the re-excavation and extension of trenches dug by Professor Colin Renfrew in 1973.
Geophysical surveys will also be undertaken to investigate the location of standing stones and other features within the monument.
Dr Jane Downes of the Orkney Research Centre for Archaeology (ORCA) and Dr Colin Richards, of the University of Manchester, are the project directors and will lead the programme of fieldwork and subsequent analysis of its findings.
Dr Downes said: “Because so little is known about the Ring of Brodgar, a series of assumptions have taken the place of archaeological data. The interpretation of what is arguably the most spectacular stone circle in Scotland is therefore incomplete and unclear.
“Although the excavations 35 years ago were undertaken to obtain dating material and establish chronology, they failed due to the limitations of available dating techniques at the time. The advanced new techniques now at our disposal mean that this time our investigations should establish when the Ring of Brodgar was built and help us learn a great deal more about it.”
Dr Richards added: “At present, even the number of stones in the original circle is uncertain. The position of at least 40 can be identified but there are spaces for 20 more. Our investigations will therefore also focus on the architecture of this fascinating ancient site.”