Structures Twenty-Eight, Twenty-Three and Thirty-Three

Structure Twenty-Eight

The remains of Structure Twenty-Eight lie beneath its replacement, Structure Twelve.

Built around 3200BC, Twenty-Eight was very similar to its contemporaries, Structures Seventeen and Eighteen – all perhaps raised using a standardised “template” for the earlier piered buildings.

But although it shared architectural elements, Structure Twenty-Eight stood out as a masterpiece in stone – the finest example of Neolithic construction in the south-eastern section of Trench P.

It earned this accolade not just for the quality of its masonry but for the effort that went into selecting and sourcing the building material. Structure Twenty-Eight was clearly meant to be an impressive construction from the outset.

The building’s inner wall face, for example, used fine flagstone with distinctive pink bands, or laminae, within the flagstone. When quarried, this stone splits beautifully into large blocks with sharp edges and flat surfaces. Glacial striations on the upper surface of the blocks confirmed that they were quarried in Orkney’s West Mainland, with geological survey indicating a potential source on the Ness of Brodgar peninsula.

The quality of Structure Twenty-Eight’s construction and finish suggests that it served as the model for the construction of Structure Twelve. There is no doubt that it also provided the building materials.

The same pinkish stone is also found in Structure Twelve and clearly came from the dismantled walls of its predecessor. It also appears in the much later Structure Twenty-Six, strongly suggesting that stone robbed from Twelve was subsequently used in its construction.

Although it was dismantled to allow the construction of Twelve around 3100BC, enough of Twenty-Eight survived to show it was originally a sub-rectangular building that sat slightly askew to Twelve’s north-north-east/south-south-west orientation.

Originally about 12 metres long and 8.6m wide, Structure Twenty-Eight was slightly smaller than its successor. When first raised, its interior measured c8.7 metres by 5.5 metres, with a single pair of opposing piers. By the end of the 2024 season we had identified four of Twenty-Eight’s corner buttresses – two from its primary phase and two from the secondary phase, when the building was truncated and a curving wall inserted across the northern end.

Since 2021, excavation in the north end of Structure Twelve had suggested subsidence – episodes that required continual infilling and repair. Initially this was blamed on what we through to be a “mega-drain” – a huge, covered drain running in a north-easterly direction from Twelve’s south-western corner to Structure Ten.

Although the evidence saw us move away from the mega-drain theory, the structural problems apparent in Twelve, and the sheer number of features and voids beneath the building, does suggest there were problems before Twelve was built – particularly around its north end.

And it seems these northern issues affected Structure Twenty-Eight.

At some point in its history – perhaps not long after construction – something happened that saw Twenty-Eight reduced in length by about two metres. Its original inner wall face and the northern corner buttresses were dismantled and the material used to insert a new, curving wall across the northern end.

The fact that the new wall lay just inside a known area of subsidence within Twelve, implies that there were longstanding issues in the vicinity that may also have been problematic for Twenty-Eight’s original northern wall. And severe enough to require its removal.

2024: A section of the multiple layers of flat stone slabs in Structure Twelve’s northern end. An attempt, we think, to remedy subsidence and floor collapse in this area of the building. (📷 Sigurd Towrie)

No evidence for hearths was found within Structure Twenty-Eight, but given its length – and similarities to other buildings – two seems likely.

Excavation revealed no definite evidence of Twenty-Eight’s entrance, but it is likely that it was in the eastern side, perhaps south of the central pier.

In Structure Twelve’s eastern annexe a sizable “standing stone” divided the cell in two. Unlike the clear alignment between Structure One and the “central standing stone“, the annexe stone did not appear to relate to Twelve’s east entrance.

This suggests it might relate to an earlier building. If that was Twenty-Eight, we might indeed be looking at a doorway in the southern section of the east wall.

Structure Twenty-Eight stood less than a metre to the south-west of Structure Twenty-Three (see below), a contemporary building which survives only as a curved section incorporated into Twelve’s northern annexe. At some point in their lives, the narrow gap between to two earlier buildings became the focus for incised decoration.

It seems there was little, or no, delay between the demolition of Structure Twenty-Eight and the construction of Twelve. As we’ve seen, it seems likely that Twenty-Eight was also plagued by structural instability due to underlying constructions.

What is certain, however, is that the construction sequence under Structure Twelve was considerably more complex than originally thought.

2023: The complex sequence revealed in the sondage beside Structure Twelve’s west central pier.

In 2023, a sondage inserted beside Twelve’s west central pier revealed multiple features beneath the building. One of these related to Structure Twenty-Eight, but others included what may be part of Structure Twenty-Four – represented by a ridge across the interior of Twelve – as well as voids and assorted stonework. This included a stack of masonry set in an oval pit to underpin Structure Twelve’s west central pier, which demonstrates that the builders knew that this area was unstable due to the presence of Structure Twenty-Four.

Supervisor Jim Rylatt has proposed that Twenty-Four – which was represented by a ridge running across the interior of Twelve – might be traced beyond Structure Twenty-Six to the eastern edge of Trench P, and probably represents an early, substantial drain.

Clearly a lot was going on in the years before Twelve’s construction. Exactly what could not be fully understood through the limited window offered by the small, narrow sondage. But the situation revealed beneath Twelve reinforces that building at the Ness was a constant, continuous, process. We may be looking at a scenario where some structures stood for barely a generation before being dismantled and replaced.

Was this a structural necessity? Or simply that the new generation wanted to create something larger and more impressive than the buildings raised by their forebears?

Whatever the reason, when Structure Twenty-Eight’s time was over the building was carefully dismantled and Structure Twelve rose from its remains.

Parts of the earlier building were re-used as wall foundations for Twelve, while other sections can be seen in the south, east and south-west of the later building. In the south-eastern corner these must have gradually emerged through Twelve’s floor as the surrounding deposits consolidated and subsided. The presence of this “ghost” structure may have been one of the reasons that Twelve’s southern doorway went out of use and was blocked.

Rubble from Twenty-Eight also poked through the floors of Structure Twelve’s south-western and south-eastern recesses, which may have required the use of raised benches or platforms to create level surfaces. Elements of the foundations of Structure Twenty-Eight’s secondary, curved wall also emerged in Twelve’s north-west alcove, truncating deposits within the slow cooker pit and probably pushing out the central and southern elements of the orthostatic lining of the slow cooker.

2023: 3d model of Structure Twelve with elements of Structure Twenty-Eight visible underneath.

Structure Thirty-Three

To the east of Twenty-Eight, and probably contemporary with it, is Structure Thirty-Three – a building represented only by a single, curving wall.

Around 2900BC, the northern section of Thirty-Three was truncated by the construction of Structure Ten, although traces probably remain beneath its outer paving. Before that it was probably similar in size and shape to Structures Fourteen, Seventeen and Eighteen.

Although it probably stood at the same time as Twenty-Eight, Structure Thirty-Three must be later than Twenty-Three because it is built up against its outer wall face. This is evident in Twenty-Three’s northern wall, where the stones are laid up against Thirty-Three’s outer face.

The paving associated with Structure Twenty-Three also respects the wall of the earlier Thirty-Three, as does the orthostatic panel on its south-eastern side.

Structure Twenty-Three

Structure Twenty-Three stood less than a metre to the north-east of Structure Twenty-Eight.

All that remains of this building is a short section of curved wall that was, much later, incorporated into the northern entrance annex added to Structure Twelve in its second phase of use.

Because the bulk of Twenty-Three was destroyed and the surviving wall sits in an area packed with the remains of of numerous constructions, we know little about it.

The curvature of the wall suggests Twenty-Three may be on a par, size-wise, with Structure Sixteen (see above)

At their closest point, Structures Twenty-Eight and Twenty-Three were a mere 85 centimetres apart, creating a narrow passage that was found to be extensively marked with incised decoration.