The Secrets of Stonehenge

Interviewer: Lucy Vernall (Interviewer, Ideas Lab)
Guest: Dr Paul Garwood
Recorded: 12/08/2014
Broadcast: 09/09/2014

Intro VO: Welcome to the Ideas Lab Predictor Podcast from the University of Birmingham. In each edition we hear from an expert in a different field, who gives us insider information on key trends, upcoming events, and what they think the near future holds.

Lucy: Our guest today is Dr Paul Garwood, who is Senior Lecturer in Archaeology and has been taking part in the Stonehenge Hidden Landscapes project.  Paul, we’re very excited about this. Thank you very much for joining us to tell us something about it – not everything. So perhaps you could start off just by introducing us to the project and to your role within it. 

Paul: OK, the Stonehenge Hidden Landscapes project has been running for five years since 2010 is the largest geophysical survey project, archaeological geophysical survey project, ever mounted globally and the aims of it is to survey the area around Stonehenge within the World Heritage Site, both above ground and also below ground, to create a seamless map, a three dimensional map of the landscape that we can see but also the hidden landscape beneath the surface. 

Lucy: So we’re not just talking about what we think about as the Henge but we’re talking about quite a large area around that. 

Paul: Well the area around Stonehenge since the 18th Century has been recognised as a landscape which is chocabloc full of various monuments. Some of them date to the same time as Stonehenge, some predate and some postdate the monument. Of course the focus of attention has always been on that central stone built thing that everybody knows about, but it’s very difficult to make sense of this thing without understanding the landscape around it, to put it into context in terms of the whole use of the landscape. 

Lucy: Because people use it as a ritual process and they use it in all sorts of different ways.  

Paul: Well the landscape already had a sacred significance before Stonehenge was built. One of the largest middle Neolithic, so around 3,000 – 3,500 BC, monuments known in the British Isles was built in the Stonehenge landscape to the north of Stonehenge at a time when there wasn’t a Stonehenge. So the landscape already had a deep history if you like of occupation, inhabitation and sacred significance, to which Stonehenge itself initially merely added to before later on it became the centre of attention and of course is still the centre of attention for us but in fact for large periods after it fell out of use it was something really in marginal landscape and so its meaning has always changed over the centuries and the millennia. .

Lucy: So when you say it’s the biggest geophysical remote sensing survey in the world, is that in terms of detail or is that in terms of the amount of space that you’ve covered?

Paul: Both. The scale of the Stonehenge Hidden Landscapes project is unprecedented. It’s roughly just short of 12 square kilometres of survey, combining a multiplicity of techniques. So we’ve been using magnetometry, resistivity survey, ground penetrating radar, a range of other quite innovative methods as well as topographic surveys and terrestrial laser scanning.  What that allows us to do is to model the terrain and monuments on the surface in three dimensions, to map the sub-surface features using magnetometry for example in two dimensions, but also to use ground penetrating radar to provide volumetric data for features and monuments beneath the surface.  So put all that together and you can create a seamless map over 12 square kilometres and what’s below ground, on the ground surface and if you like those islands of archaeology monuments poking up above the surface as it now exists.

Lucy: So it’s new technology and new methodology as well.

Paul: The technologies involved have existed for some time but it’s the particular organisation of them and the very high resolution versions of those technologies which we’re now able to use, in particular motorisation.  So motorisation of ground penetrating radar, motorisation of magnetometry for instance, allows for very rapid but at the same time very very precise high resolution survey work to be conducted and it’s really only on that basis that it’s been possible for us to have this ambition and to undertake this work, that equipment mostly provided by the Ludwig Boltzmann Institute for Archaeological Prospection and Virtual Archaeology, based in Vienna, they provided most of that mechanised, motorised equipment. 

Lucy: So of course, what we all want to know is what have you found?! I know that’s going to be gone into in a lot more detail at the big press conference at the British Science Festival but what can you hint at, Paul?

Paul: Well, I think the discoveries are such that at a very big scale, the survey represents a game changing moment really because what the mapping allows us to do is ask questions about whole areas, not just single monuments or points within the landscape, but how all of this joins together.  So the future questions we’ll ask about the landscape on the basis of the work that we’ve been doing are the kinds of questions we could never ask before about whole areas of landscape. Of course the attention is often focused on Stonehenge and for that famous monument built in the middle part of the third millennium BC, we are providing a new context for what’s going on in the landscape around Stonehenge.  So for instance, we now know that there are far more small monuments which had sacred significance and which were being used ritually which are contemporary with Stonehenge and almost certainly used at the same time that Stonehenge was being used in the area immediately around the monument itself.  So Stonehenge did not stand in isolation but rather was part of a very densely inhabited landscape where a range of activities were taking place and a multiplicity of different small foci, like small shrines, small cult centres, around the central one.  In addition to that, we are for the first time able to make a direct link between the Stonehenge architecture and other architecture in the landscape around because of the discovery of two pits in the great cursus, this huge earlier monument to the north, but these are located on solstitial alignments, as viewed from the hill stone, one of the stone settings on the periphery of Stonehenge itself.  So for the very first time there's a celestial set of alignments that are linking features in the wider landscape of the Stonehenge complex itself.  In addition to that, there are a whole host of later monuments in the Stonehenge landscape. There are early Bronze Age burial monuments in their hundreds and we are surveying a large number of those. Many we knew about before but because we can see beneath the surface, we see them in a completely different light. We realise they’re often multi-phased; they had long histories in their own rights over hundreds of years in the early Bronze Age. We are seeing entire agricultural landscapes, particularly in later history in the later Bronze Age and Iron Age when the landscape was divided up. Stonehenge was no longer the focus of attention and the landscape was broken up, settlements were created within the wider landscape and Stonehenge became a kind of more marginal feature within this new landscape order. So there’s an Iron Age, there’s Roman material; there’s Medieval and so forth. It’s fantastic.

Lucy: So the culmination of five years of hard work. Will there be another phase of research at Stonehenge or is the next thing to use are the same principles somewhere else?

Paul: The search at Stonehenge never stops!  There's always something but we are not leaving it to one side at all. The data sets that we’ve generated, of course we’re going to be publishing these in the next few years. There will be a host of research papers that will also accompany those big monographs that we’ll be producing.  But we’re certainly seeing this as the stepping stone towards future work, so I think clearly geophysical survey involves only scanning things remotely and what you can’t get from that easily is any kind of dating evidence and of course the only way to get dating evidence is to dig things up. So one of the things we’ll certainly be looking at is a programme of fieldwork including further survey of a variety of descriptions, but also highly targeted, very very specific excavations to recover cultural material, environmental sample materials and above all, dating evidence, so we can start to give a chronology to many of the features that we’ve now seen, some of which are unique, some of which we think we know what  they are but we’re not absolutely certain, and things which we would very much like to be able to date, again to give that broader context for Stonehenge before, during and after the use of the monument. 

Lucy: All very exciting. Thanks very much Paul for coming in to tell us about it. 

Paul: My pleasure.

Lucy: And we’re looking forward to hearing more after the big press conference at the British Science Festival. The press conference is on the 9th September so hopefully by the 10th there will be world media coverage of everything you’ve been doing over the past five years. 

Paul: There will be lots more detail and lots of exciting news. 

Lucy: Thank you very much. 

Paul: Thank you. 

Outro VO: This podcast and others in the series are available on the Ideas Lab website: There's also information on the free support Ideas Lab has to offer to TV and radio producers, new media producers and journalists. The interviewer and producer for the Ideas Lab Predictor Podcast was Sam Walter.