Category Archives: henge

Foot of Avebury Down Dig – Day 7


Dig with a view: our Foot of Avebury Down site with the green banks of Avebury henge in the middle distance© National Trust / Nicola Snashall

One of the great privileges of working and digging in the Avebury landscape is that you become familiar with looking at it from some very different perspectives to the ones you’ll find in the text books. From our site at the Foot of Avebury Down you get a fantastic view of the henge which really shows how it sits on a plateau within a landscape bowl surrounded by hills.

Today we’ve opened up another trench in the pasture field (Trench 3) to see if we can spot any fall-off in the concentration of stone working waste that we’re finding. And so far the indications are that its continuing, though we’ll have to wait and see if we get the same quantities.

As a major strand of the Living with Monuments Project we’re exploring the make-up of the soils and the ancient environment in and around Avebury. This will help us work out what the environment was like in the past. Where were the trees? Where was the grassland? Did this change through time? Are their indications of ancient cultivation? Where were the  palaeo-channels (ancient water courses)? But it will also help us locate areas where we might find well-preserved archaeology that may be masked by colluvium (soils washed down from hill-tops) or alluvium (soils dumped from rivers and streams overtopping their banks).

MA Snail box

No prizes for guessing Mike’s specialist subject… © National Trust / Nicola Snashall

And today we had our two ancient environment detectors-in-chief  out in the field (literally) with us. Dr Mike Allen (Allen Environmental Archaeology) knows everything there is to know about chalkland soils and snails. As Mike would tell you snails are fussy little critters, with particular species only living in very particular micro-habitats. Which is great for archaeologists working on chalk – where pollen doesn’t survive well – because it gives us a way of mapping the ancient environment.

The other half of our ancient environment tag team is Professor Charly French (Cambridge University). Charly is an expert in soil micro-morphology and mapping palaeo-hydrology (ancient water courses). Our hope is that, coupled with the Electro Magnetic Induction surveys being carried out by Dr Philippe de Smedt (Ghent University), in five years time our understanding of what different places in and around the Avebury landscape looked like at different times during the Neolithic and Bronze Age will have been transformed. And all this starts with two men in a wheat field…


Two men in a field: Charly and Mike get down to work  © National Trust / Nicola Snashall

SQUARING THE CIRCLE: Archaeological detectives discover ‘secret square’ beneath world-famous Avebury stone circle

New archaeological surveys reveal unique square megalithic monument at the heart of the World Heritage Site.

Archaeologists have found a striking and apparently unique square monument beneath the world famous Avebury stone circle in Wiltshire.

The UNESCO World Heritage Site, cared for by the National Trust, was built over several hundred years in the 3rd millennium BC and contains three stone circles – including the largest stone circle in Europe which is 330m across and originally comprised around 100 huge standing stones.

A research team led by the University of Leicester and University of Southampton used a combination of soil resistance survey and Ground-Penetrating Radar to investigate the stone circle.

Their work was funded by the Arts and Humanities Research Council (AHRC) and supported by the National Trust, as well as archaeologists from the University of Cambridge and Allen Environmental Archaeology.

Dr Mark Gillings, Academic Director and Reader in Archaeology in the School of Archaeology and Ancient History at the University of Leicester, said: “Our research has revealed previously unknown megaliths inside the world-famous Avebury stone circle. We have detected and mapped a series of prehistoric standing stones that were subsequently hidden and buried, along with the positions of others likely destroyed during the 17th and 18th centuries. Together, these reveal a striking and apparently unique square megalithic monument within the Avebury circles that has the potential to be one of the very earliest structures on this remarkable site.”

Avebury has been subject of considerable archaeological interest since the 17th century. The discovery of new megaliths inside the monument was therefore a great surprise, pointing to the need for further archaeological investigations of this kind at the site. The survey took place inside the Southern Inner Circle, contained within the bank and ditch and colossal Outer Stone Circle of the Avebury henge. Excavations here by the archaeologist and marmalade magnate Alexander Keiller in 1939 demonstrated the existence of a curious angular setting of small standing stones set close to a single huge upright known since the 18th century as the Obelisk. Unfortunately, the outbreak of war left this feature only partially investigated.


Model of square stone setting

A possible reconstruction of the stone settings within the southern inner circle incorporating  Keiller’s discoveries and those of the new geophysical surveys


Dr Joshua Pollard from the University of Southampton said: “Our careful programme of geophysical survey has finally completed the work begun by Keiller. It has shown the line of stones he identified was one side of a square of megaliths about 30m across and enclosing the Obelisk. Also visible are short lines of former standing stones radiating from this square and connecting with the Southern Inner Circle. Megalithic circles are well known from the time when Avebury was built during the late Neolithic (3rd millennium BC), but square megalithic settings of this scale and complexity are unheard of.”

Dr Nick Snashall, National Trust archaeologist at Avebury, said: “This discovery has been almost eighty years in the making but it’s been well worth waiting for. The completion of the work first started by Keiller in the 1930s has revealed an entirely new type of monument at the heart of the world’s largest prehistoric stone circle, using techniques he never dreamt of.  And goes to show how much more is still to be revealed at Avebury if we ask the right questions.”

figure_3 (1)

The reconstructed ground plan of the Southern Inner Circle combining the results of the current survey with the 1939 excavation

The archaeologists who undertook the work think the construction of the square megalithic setting might have commemorated and monumentalised the location of an early Neolithic house – perhaps part of a founding settlement – subsequently used as the centre point of the Southern Inner Circle. At the time of excavation in 1939 the house was erroneously considered by Keiller to be a medieval cart shed.

If proved correct, it may help understand the beginnings of the remarkable Avebury monument complex, and help explain why it was built where it was.

The research team is currently compiling their research into a paper for academic publishing.

You can access a full technical report here


The work was part of the ‘Living with Monuments project’, funded by the Arts & Humanities Research Council (AHRC).  The Living with Monuments project is five years (Sep 16 – Sep 21)  and AHRC funding amounts to £780,831. It is a collaborative project involving archaeologists from the Universities of Leicester, Southampton and Cambridge, the National Trust, and Allen Environmental Archaeology.

The survey was directed by:

Dr Mark Gillings,  University of Leicester

Dr Joshua Pollard, University of Southampton

Dr Nick Snashall, National Trust, Archaeologist for Stonehenge and Avebury WHS

Dr Ros Cleal, National Trust, Curator of the Alexander Keiller Museum, Avebury