Setting boundaries – the ‘Great’ and ‘Lesser’ Walls of Brodgar

“Built on a monumental scale […] these walls created impressive facades that would have been encountered by people moving towards the site from the Bridge of Brodgar to the south-east, and from the undulating ground to the north-west. Working with the waters on either side, they may have formed a coherent enclosing boundary for part of the sequence.”
Nick Card and Mark Edmonds. Setting Boundaries
The Ness of Brodgar: As it Stands
. (2020)


Northern Boundary Wall representation

During the early years of the excavation, evidence seemed to point towards the Ness complex being an enclosed precinct – surrounded by a large, stone wall.

At the root of this were the results of preliminary geophysical surveys which indicated a large feature – with a possible entrance – running the width of the peninsula to the north-west and a second to the south-east.

Intermittent traces of linear features also seemed to run between these two at either side. These were interpreted as connecting walls.

Interpretation of the gradiometer 2013 gradiometer survey results. (ORCA)

Excavation to the north and south of the site confirmed the existence of the large northern boundary wall (dubbed the “Great Wall of Brodgar”) in 2007, followed by its southern counterpart (the “Lesser Wall of Brodgar”) in 2009.

Attempts to confirm the existence of a pair of walls connecting the two have been unsuccessful and, in 2018, excavation seemed to rule out the idea that the site was completely enclosed.

The northern boundary wall

The 'Great Wall of Brodgar' in 2021, curving around Structure Five's northern end (left) before coming to an abrupt stop. (Sigurd Towrie)

The ‘Great Wall of Brodgar’ in 2021, curving around Structure Five’s northern end (left) before coming to an abrupt stop. (Sigurd Towrie)

The first physical encounter with the “Great Wall” was in Trench J, where excavation revealed a corner section of the huge, four-metre-wide (13ft) barrier. The well-built wall curved beautifully around the northern end of Structure Five but then abruptly stopped.

Trench J in 2008. The ‘Great Wall’ is shown in red, with Structure Five in yellow.

Two trenches, M and N, dug to the south-west of Trench J, confirmed the wall continued across the width of the Ness.

The fact it curved at the northern end and travelled a short distance suggested it had either continued along the length of the Ness and had either been robbed of stone or joined another northwest-southeast running wall.

In Trench M, around two metres from the outer wall face were traces of a two-metre-wide ditch, around 60cm deep, that ran parallel to the wall across the Ness. It was also clear that at some point in its later life at least a section of the wall was widened to six metres.

Great Wall of Brodgar

The exposed section of the northern boundary wall, curving around Structure Five, in 2019. (Scott Pike)

This addition was perhaps added after the original wall had collapsed, or partially dismantled, and may have been an attempt to monumentalise the original construction or enhance its entrance.

Whether the extension related solely to the area around the entrance, or the entire northern wall remains to be seen.

The excavated section of the northern boundary wall survives to a height of 0.65 metres but obviously we can’t tell the heights this monumental construction once reached. The sheer width of the lower courses could indicate a wall of considerable height.

In addition, compared to its Trench J neighbour, Structure Five, the wall’s basal course of stone was found to be deeply pressed into the underlying glacial clay. This suggests it supported a considerable weight – and height – of walling.

The northern wall was built on virgin ground – constructed directly on top of natural boulder clay. Although this hints that it was probably early in the site’s history, we can’t say for sure.

Until recently the fact the wall seemed to respect Structure Five and curved around its northern end led us to believe the two were roughly contemporary, dating to around 3300BC.

We had thought that the building’s north end was primary and that the southern end was perhaps a later addition. But in 2021, it became clear the opposite was the case.

Trench M, opened to investigate the extent of the ‘Great Wall of Brodgar’. (ORCA)

The elliptical northern end of Structure Five was the later addition and one that was raised on natural glacial till. Clearly exposing, and building on, the natural clay surface happened on multiple occasions and perhaps over an extended period of time.

The relationship between the wall and Structure Five is much more complex than initially thought. They may well still be contemporary but could equally be separated by years, decades or longer.

Whenever the wall was first raised, it seems that by c3000BC – around two centuries after the construction of the piered buildings in Trench P and a century before Structure Ten – the wall had been dismantled to its current height [1].

Why was the wall demolished?

Probably because it no longer served as a boundary to the site and had been replaced.

An exploratory trench over the wall revealed what could be more buildings, and a possible hearth. This and geophysical scans suggest that structures spilled out to the north-west, beyond the confines of the wall.

In addition, the remnants of another large ditch have been found to the north-west, discovered in section when the shore path along the Loch of Harray was built. Four metres deep and one metre deep, this huge earthwork – like those around the Ring of Brodgar, Stones of Stenness, Maeshowe and Ring of Bookan – seems to have enclosed the buildings we now suspect lay beyond the “Great Wall”.

This suggests that the boundaries were not fixed but, like the Ness complex itself, changed over time:

“They made dramatic statements for a time before being abandoned, dismantled or reworked to serve other purposes.” [1]

The southern boundary wall

Southern boundary wall emerges (ORCA)

The top of the southern boundary wall emerges in Trench R in 2009. (ORCA)

In 2009, another exploratory trench was inserted over a large, linear geophysical anomaly to the south-east of Trench P.

Trench R confirmed the presence of a second isthmus-spanning wall but one that was considerably different to its northern counterpart.

With a width of two metres (6ft 7in), the southern boundary wall was narrower but survived to a height of c1.8 metres (5.9ft).

The outer face of the southern boundary wall revealed. (ORCA)

The outer face of the southern boundary wall revealed. (ORCA)

It exhibited finer masonry and was built using flagstone slabs, rather than large stone blocks, and had been raised on top of the remains of earlier buildings. These early structures have yet to be excavated or dated. The wall’s outer face – the side facing the Stones of Stenness – was also paved along its base.

Unlike the northern wall, the geophysics did not should anything that could be interpreted as an entrance. It does, however, appear to relate to the two standing stones at its north-eastern end, perhaps suggesting they were part of an entrance feature.

The occurrence of stone pairs at entrances is something we have pondered here.

The position of the 'Lesser Wall' in relation to the two Lochview standing stones. (ORCA)

The position of the ‘Lesser Wall’ in relation to the two Lochview standing stones. (ORCA)

Although the two boundary walls probably flanked the Ness site at the same time – for a period at least – the southern wall remained standing until the abandonment of the complex. By this time, long after the northern wall had been dismantled, its significance, like the monumental buildings it contained, had perhaps waned – even forgotten.

The paving running along the base of the 'Lesser Wall' revealed in 2010. (ORCA)

The paving running along the base of the ‘Lesser Wall’ revealed in 2010. (ORCA)

The elusive connecting walls

Sarah excavating at the bottom of the 'Lesser Wall of Brodgar' in Trench R in 2010. (ORCA)

Sarah excavating at the bottom of the ‘Lesser Wall of Brodgar’ in Trench R in 2010. (ORCA)

The geophysics scans suggested that the northern and southern boundary walls both ran across the width of the Ness and curved around at edges of the isthmus. As we’ve seen this was confirmed in Trench J, with the exposed section of the “Great Wall” curving beautifully at its northern end.

This led to the suggestion that the two walls were connected by another pair running north-west to south-east and which completely enclosed the site.

Although geophysics showed apparent linear features running between both ends of the two confirmed boundary walls, excavation has drawn a blank.

Although the northern wall definitely curves and runs south-east for a short distance, excavation in 2018 showed that it did not continue south-eastwards along the length of the Ness. Investigating the clay beneath huge stones in the wall revealed, as expected, large depressions caused by the weight of the construction.

These were completely absent in the area where it was once thought the wall continued. So, it seems the “Great Wall” stopped abruptly. At this cut-off point the boulder clay was unmarked – something it wouldn’t be had a former section of the wall been dismantled or robbed.

At the opposite, western, side of the Ness what appeared to be cropmarks suggesting a long, linear feature following the path of a hypothetical connecting wall were noted from aerial photographs in 2017.

Aerial photo from 2016 showing the path of the cropmark (solid line) suspected to be the route of the enclosing wall. (Scott Pike)

A new trench – Trench Y – was opened in 2018 but no definitive evidence for a wall was found. From both sides of the Ness, the evidence there were no connecting walls was stacking up – at least not on a par with the northern and southern examples.

While it may be that a less substantial boundary marked the south-western and north-eastern edges of the complex, there is another possibility.

We know that walls were not the only things that separated and defined space. In Orkney the most obvious examples are the huge ditches that surrounded the Ring of Brodgar, Ring of Bookan, Maeshowe and the Stones of Stenness.

At other sites throughout Britain and Ireland, water features were also drawn on to enclose or define areas [1]. The concept of water as a boundary in Neolithic Orkney has been suggested before. Professor Colin Richards has argued that the ditches around the Stones of Stenness, Maeshowe and the Ring of Brodgar were all water-filled — at least some of the time — further restricting access to the interior of the monuments, physically and symbolically [2].

As well as containing and enclosing the monument, the Ring of Brodgar’s ditch and two opposing causeways controlled movement through the stone circle.

This north-west – south-east movement may have applied to the entire Ness, a procession that was interrupted and defined by a series of walls and bounded on both sides by the waters of the lochs.

When it came to the Ness, perhaps:

“… a limit of sorts was set by the isthmus itself, and by the water of the two lochs. Although water levels had been lower at the beginning of the period, by the late Neolithic, the loch margins were not that far removed from where they are today. In these conditions, the line between land and water may have served as an equivalent for walls.” [1]


  • [1] Card, N. and Edmonds, M. (2020) Setting boundaries. In In Card, N., Edmonds, M. and Mitchell, A. (eds) The Ness of Brodgar: As it Stands. The Orcadian: Kirkwall.
  • [2] Richards, C. (1996) Henges and Water: Towards an elemental understanding of monumentality and landscape in Late Neolithic Britain. In Journal of Material Culture, 1(3), pp.313-336.