Geophysics results confirm enclosure walls at north-western end of Ness complex

Our two-week project to resurvey the Ness excavation site came to a successful end last Friday – with some very interesting preliminary results.

Led by Paul Durdin, we carried out magnetometer and higher-resolution resistivity surveys across the site and down as far as the shore of the Stenness.

The first set of resistivity results allowed us to home into specific areas of the site, where allowed us to differentiate between some overlapping structural features in the ground.

The huge amount of data gathered needs to be carefully examined and imported into our GIS system, but on first glance the survey results confirmed what we already suspected following excavation – although with a few interesting twists.

Firstly, it will come as no surprise that it looks like we have more Neolithic buildings outside the trench areas. Given we had excavated less than ten per cent of the site, we had long known that would be the case.

But what soon became clear during the survey process was that our earliest thoughts about an enclosing wall had been correct.

For many years we believed that the bulk of the Ness complex was enclosed, with a pair of connecting walls running between the northern and southern boundary walls. This stemmed from the early geophysical survey results but, by 2019, doubts were growing due to a lack of excavation evidence.

Then, in 2024, a section of a huge wall was revealed running north-west to south-east to the north of Trench P. Based on the similarities between it and the northern boundary wall, there was no doubt we had an extension.

But what about the south-western side? Two trenches had failed to find any evidence of it.

And now we think we know why.

The new results show the “Great Wall” clearly. At both end it turns and continues in a south-easterly direction. But at the south-western end, rather than running nicely parallel to its north-western counterpart, it cut inwards slightly northwards at an angle.

Because this flaunted the usual Neolithic fondness for symmetry it meant our exploratory Trench Y was outside the path of the wall, while, in Trench X, its remains lay higher up the trench than expected and beneath later structural features.

Based on the survey results, the enclosure wall may have had multiple entrances, but like all geophysical anomalies this would have to be confirmed by excavation to say for sure.

In addition, the magnetometry scans indicate that there was not just one ditch outside the “Great Wall” wall but two – both running parallel to the wall. Neither appear to continue around the two enclosure walls, however, suggesting they were perhaps added for dramatic, or symbolic, effect – features to accentuate the monumental walling (and what lay within) when approaching the complex from the north-west.

We knew from previous survey results that there was a distinct lack of activity beyond the “Great Wall” and this was clearly highlighted by the new data, particularly magnetometry. Although we have multiple anomalies suggestive of further structures to the south-east – between Trenches P and T – at the north-western end there is a very sharp line, beyond which seems to have been a no-go area.

The 2025 surveys also suggest that the southern boundary wall – the “Lesser Wall of Brodgar” – was not contemporary with its northern counterpart but belonged to a later phase of activity. It clearly runs across the width of the isthmus but does not seem to integrate with the larger, more monumental walls surrounding the north-western end of the complex.

Again this ties in with excavation evidence, which showed that the southern boundary wall had been raised on top of earlier structural remains.

Over in the area above Trench T, the new surveys revealed the full extent of the ditched enclosure inserted into the huge Neolithic midden mound in the Iron Age. They also tie in with early accounts of the area that suggested a structure once sat in the centre.

Unfortunately, the nature of this structure remains frustratingly unclear given the amount of disturbance over the past few centuries.