Structure Twelve

2023: Structure Twelve.  (📷 Tom O'Brien)
2023: Structure Twelve. (📷 Tom O’Brien)

Built around 3100BC, Structure Twelve was one of a series of buildings – including One, Eight, and Twenty-Nine – clustered around a large, open-air paved area and standing stone.

Structure Twelve (phase one) in relation to the earlier Structure Twenty-Eight.

Twelve was raised on the remains of Structure Twenty-Eight and, in its original form, was one of the finest buildings in the Ness of Brodgar complex.

Featuring exquisitely decorated and dressed stone in its construction it was undoubtedly an impressive sight, its grandeur presumably reflecting its role or status within the site.

Twelve also continues to be one of the most complicated to excavate and it is thanks to its supervisor, Jim Rylatt, that we able are to propose this biography for the building.

There was little or no interval between the demolition of Twenty-Eight and the construction of Twelve.

With much of the material sourced from its predecessor, the result was a large sub-rectangular building, approximately 17 metres long, with 1.6-metre-thick walls standing to at least 1.5 metres high.

Structure Twelve. Phase one.
Structure Twelve. Phase one.

Three pairs of stone piers projected inwards from the walls to divide the interior into alcoves and recesses and access was by three entrances – one in the south wall, another in the north-west and a third to the east.

The eastern entrance was highly ornate, featuring decorated stonework and flanked on the outside by two standing stones. It was also the only one used throughout the life of the building and presumably its principal entrance.

The area outside the east entrance was paved – the paving probably running along the whole of the building’s eastern side and a section of the southern wall.

From the north side of the doorway, and running west into the building, were two rows of low orthostats. These held a partition – either stone slabs or wooden planks – that formed the north side of an entrance passage that also divided the interior into two rooms.

A similar feature was encountered in House Two at the nearby Barnhouse Settlement.

2021: Structure Twelve from its southern end.  (📷 Sigurd Towrie)
2021: Structure Twelve from its southern end. (📷 Sigurd Towrie)

Based on current evidence, it seems Structure Twelve was involved in the large-scale preparation of food.

Each of its “rooms” contained a large stone hearth, around two metres square.

The yellow clay floor around both hearths was pockmarked by hundreds of small stake-holes, the remnants of temporary wooden constructions – racks, tripods and spits – that were constructed and dismantled on multiple occasions.

Excavation also suggests that food was also cooked/kept warm in at least two of the side recesses, where clay pots were placed on beds of hot ash.

In the north-eastern recess a rectangular stone box – formed by five stone slabs – was sunk into the floor.

The edges had been caulked with clay and the basal stone slab found to have been discoloured by repeated episodes of applied heat.

This, together with its proximity to the hearth, suggests the box, or tank, was used to heat water using hot stones from the fire.

Abutting its eastern side was an earthfast stone anvil – a sub-rectangular flagstone pillar with a pockmarked upper surface. Hammerstones of varying size were deposited next to this anvil.

A similar earthfast anvil was associated with the probable remains of another stone box to the west, while a third had been set into the floor just inside the blocked southern entrance.

Featuring an oval perforation running through its upper half, the third anvil stone looked like a large needle.

Structure Twelve’s supervisor, Jim Rylatt, has suggested this may have been used to clamp long bones so they could be broken open to reach the marrow.


The splendour of Structure Twelve did not last long.

It, like most in Trench P, had been erected on top of an earlier building, in this case Structure Twenty-Eight.

Jim Rylatt explained:

“It is clear that they were exceeding their understanding of building technology, They had levelled the remains of Structure Twenty-Eight and created a flat platform to build Structure Twelve. This probably involved some form of deliberate compaction of the midden fill within the basal walls of Structure Twenty-Eight.
“However, they don’t seem to have appreciated the fact the midden would continue to compress under the weight of the new building, while the remaining stone foundations of Structure Twenty-Eight would not.”

The shaky foundations, together with the weight of the stone-tiled roof, saw Twelve’s walls slump. Despite efforts to shore up the collapsing roof with substantial posts, it eventually came down when the southern wall toppled outwards.

The roof collapse undoubtedly affected the building’s upper walls. The north-eastern internal pier toppled and entire sections of the east wall may also have been brought down.

Rebuilding and remodelling

Structure Twelve. Phase two.
Structure Twelve. Phase two.
The rebuilt southern wall of Structure Twelve. The poor quality of the rebuild is highlighted where the replacement wall was raised on top of the rubble of its predecessor.  (📷 Sigurd Towrie)
The rebuilt southern wall of Structure Twelve. The poor quality of the rebuild is highlighted where the replacement wall was raised on top of the rubble of its predecessor. (📷 Sigurd Towrie)

The catastrophic collapse saw Structure Twelve remodelled together with some decidedly poor-quality repairs.

The collapsed southern wall was completely rebuilt – but not well. In the south-western corner, for example, the rubble from the collapse was simply left and the new wall built on top.

The resulting masonry is not an impressive sight, suggesting the southern end of the building was perhaps not meant to be seen by visitors.

The southern and north-western entrances were blocked and a door punched through the north wall.

The new entrance led into a particularly shoddy annexe that was tacked on to Structure Twelve’s northern end.

The construction of the annexe was as inglorious as its architecture.

The northern entrance, added in the second phase, looking into the annex.  (📷 Sigurd Towrie)
The northern entrance, added in the second phase, looking into the annex. (📷 Sigurd Towrie)

Rather than clear away a huge, bulbous mound of midden heaped against the north wall, the Neolithic builders simply dug into it and built the annex walls up against the cut sides.

While digging they exposed a low wall. This was all that remained of a section of Structure Twenty-Three – an earlier building contemporary with Twenty-Eight – which they adapted to form the annex’s north-eastern wall.

While their construction technique was undoubtedly a quick solution, the annex-builders must have known it was terribly built.

Was it just meant to be temporary? Or were they simply not concerned about how their new addition – like the southern wall rebuild – looked?

One thing is for sure, the fact it survived to its present height continues to amaze. Contemplating the annex in 2021, excavation director Nick Card commented: “How that has managed to stay standing for over 5,000 years is beyond me.”

The eastern annexe

As well as the northern annexe, a teardrop-shaped cell was erected on top of the paving outside the eastern entrance.

This addition formed part of a new north-south passageway leading to the doorway.

Like its northern counterpart, the small eastern annexe was incredibly poorly built, relying on the the heaps of midden accruing outside the building for structural stability. The shoddiness of the construction strongly suggests that neither annexe was roofed.

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Changing times?

Structure Twelve. (Jim Rylatt)
2021: Structure Twelve. (📷 Jim Rylatt)

Structure Twelve’s inferior remodelling is intriguing. Although the building was clearly still considered important enough to rebuild, the haphazard nature of the work suggests something had changed.

Had Twelve, once the jewel in the Ness’ crown, lost its significance?

Jan's post-hole in the south-eastern corner of Structure Twelve, overlying the wall line of Structure Twenty-Eight. (Sigurd Towrie)
Post-hole, perhaps to shore up the roof, in the south-eastern corner of Structure Twelve, overlying the wall line of Structure Twenty-Eight. (📷 Sigurd Towrie)

Was appearance less important than it once was? Were there less resources available?

Or was it a reflection of the status of the Ness complex as a whole?

A 2017 reanalysis of radiocarbon and luminescence dates proposed that Neolithic Orcadian settlement was linked to “unsustainable local political tensions and social concerns”. [3]

The new data suggested that a peak of activity on and around the Ness of Brodgar peninsula was followed by an Orkney-wide decline.

From around 2800BC, settlement intensity decreased throughout the islands. Occupation picked up again in the 27th and 26th centuries BC but not around the Ness of Brodgar.

The Stenness/Brodgar area of the Orkney Mainland “appears to have ceased to serve as a significant place of human dwelling.” [3]

The authors suggested that Orcadian society in the third millennium BC was caught in the unsustainable, and ultimately self-destructive, pursuit of prestige, social status and influence.

Looking north over Structure Twelve in 2015, with Structures One, Eight, Ten and Fourteen in the background. (ORCA)
2015: Looking north over Structure Twelve, with Structures One, Eight, Ten and Fourteen in the background. (📷 ORCA)

Notions of ancestral links and descent were key and the rush for social standing manifested through monument building. [3]

The resulting competitive and unstable society [4] saw rivalries played out as groups sought to outdo each other with increasingly elaborate constructions [5] – investing “time and labour in monuments relating to deities, ancestors and origins that stretched well beyond the shores of Late Neolithic Orkney”. [3]

How did this proposed quest for prestige affect settlement?

The suggestion is that the obsession with monuments and status pushed Neolithic society in Orkney to breaking point.

We don’t yet have a date for Twelve’s collapse so cannot say whether the proposed decline in activity around the Ness of Brodgar is related to the poor-quality rebuild.

However, one thing is without doubt – Structure Twelve was raised again.

As before, activity centred around the two hearths and food preparation dominated.


One of the three ‘Butterfly Stone’ fragments found outside Structure Twelve’s northern annex.

The reconstruction of the building did nothing to improve its foundations and, around 2700BC, further structural problems marked the beginning of the end for Structure Twelve.

The remodelled building continued to slump, and a section of the west wall collapsed, bringing down a part of the roof.

It may be that this hole was patched but it must have been clear that Twelve’s time was over.

A final feast appears to have marked the decommissioning of the building, evidence of which was found around both fireplaces.

The southern hearth sat amidst a large spread of cattle bone while its northern counterpart was partially covered by a huge deposit of Grooved Ware pottery.

Up to eight layers deep, this ran from the hearth to the northern entrance and filled the width of the northern alcove.

The scale of the deposit suggests that all the ceramic vessels in the building were carefully laid on their sides and deliberately crushed.

Thereafter the surviving roof sections either collapsed or were deliberately toppled – perhaps to seal the decommissioning deposits and the interior of the building itself. This also allowed the roof’s timber frame to be salvaged, possibly for use elsewhere.

The roof gone, Structure Twelve’ walls were partially dismantled, reducing them in height. At the same time as the interior was being carefully filled with midden it was also heaped up against the external walls, effectively burying the building.

A series of artefacts placed in the northern annex – including complete and broken pottery and a polished stone macehead – have been interpreted as closing deposits.

Among the material used to block the northern entrance were three fragments of a beautifully decorated stone slab, deeply incised with the “Brodgar Butterfly” motif.

This was almost certainly an orthostat removed from Structure Twelve – the base had a light fracture indicating that force had been applied to the top to snap it off at its (probably earthfast) base.

The three fragments of the 'Butterfly Stone' found at the north entrance of Structure Twelve in 2013. (Antonia Thomas)
The three fragments of the ‘Butterfly Stone’ found at the north entrance of Structure Twelve in 2013. (📷Antonia Thomas)

But although Structure Twelve had been abandoned it was clearly not forgotten.

The remains may have been entombed but elements must have remained visible above the surface. We know this because some time later the eastern entrance was specifically targeted by stone robbers.

Targeted by stone robbers

2019: The southern cupmarked stone at Structure Twelve's eastern entrance.  (📷 Sigurd Towrie)
2019: The southern cupmarked stone at Structure Twelve’s eastern entrance. (📷 Sigurd Towrie)

The buried remains of Structure Twelve may not have lain undisturbed for too long.

The fact the stone robbers knew exactly what they were looking for and where to find it suggests the building was targeted within living memory of its last use.

The robbers, however, were not looking for any old stone. They specifically targeted the east entrance. Their cut through the overlying midden exposed only the eastern central pier and the facing stones from the sides of the entrance passage. The precision of the cut suggests they were looking to retrieve dressed  stone rather than just building material.

After those initial forays Structure Twelve was left again – this time probably for a considerable period. Then the robber cut was revisited and enlarged to allow the extraction of stone from the east wall.

2023: Structure Twelve. (📷 Jim Rylatt)


  • [1] Richards, C. (1993) An archaeological study of Neolithic Orkney: architecture, order and social classification.
  • [2] Robin, G. (2010) Spatial Structures and Symbolic Systems in Irish and British Passage Tombs: The Organization of Architectural Elements, Parietal Carved Signs and Funerary Deposits. Cambridge Archaeological Journal 20:3, 373–418.
  • [3] Bayliss, A., Marshall, P., Richards, C. and Whittle, A. (2017) Islands of History: The Late Neolithic timescape of Orkney. Antiquity, 91(359), pp. 1171–1188.
  • [4] Richards, C. and Jones, R. (eds) (2016) The Development of Neolithic House Societies in Orkney: Investigations in the Bay of Firth, Mainland, Orkney (1994–2014). Windgather Press.
  • [5] Schulting, R., Sheridan, A., Crozier, R. and Murphy, E. (2010) Revisiting Quanterness: new AMS dates and stable isotope data from an Orcadian chamber tomb. In Proceedings of the Society of Antiquaries of Scotland (Vol. 140, pp. 1-50).
Structure Twelve: Excavation over Time