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

Structure Twenty-Eight

Structure Twenty-Eight lies beneath the remains of Structure Twelve.

Although dismantled in prehistory to allow the construction of Twelve, enough of Twenty-Eight survived to show it was a sub-rectangular building, dating to around 3200BC, with stonework that rivalled that of nearby Structure Twenty-Seven.

Based on current evidence, Twenty-Eight sat slightly askew to Twelve’s north-north-east/south-south-west orientation and was smaller than its successor – measuring c12 metres long and 8.6m wide.

Its interior measured c8.7 metres by 5.5 metres, but we have yet to reveal any internal fixtures, other than a section of its yellow clay floor.

The situation became more complex in 2023, with the discovery of a wall under Twelve’s northern end. But how this relates to Twenty-Eight is not yet clear.

It is also not clear how many piers, if any, the building had.

We had long thought that a ridge across the interior of Structure Twelve represented at least one pair of opposed stone piers. A test pit in 2023, however, showed this related to Structure Twenty-Four, a building that pre-dates Twenty-Eight!

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

Structure Twenty-Eight lay a mere 0.84 metres 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 became the focus for incised decoration.

Although Twenty-Eight shares architectural elements with Structures Seventeen and Eighteen, and the later buildings One and Twelve, it stands 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 superb quality of its masonry but for the effort that went into selecting and sourcing the building material. Structure Twenty-Eight was clearly intended to be an impressive construction from the outset.

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

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.

No definite evidence of Structure Twenty-Eight’s entrance(s) has been found but if the building had the same floorplan as Structure Fourteen, the doorway may have been in the eastern side, north of the central pier.

In Structure Twelve’s eastern annexe there is a sizable “standing stone” that divided the cell in two. Unlike Structure One and the “central standing stone“, this stone is not aligned with Twelve’s east entrance.

This suggests the orthostat relates to an earlier building. If that was Twenty-Eight, we might be looking at an entrance in the southern section of the east wall.

We don’t yet know why Twenty-Eight was replaced but it seems there was little or no delay between its demolition and the raising of Twelve. Like many of the later buildings, it may have suffered from structural instability due to underlying constructions.

A portion of its western, inner wall, for example, appears to have been supported by Structure Twenty-Four but slumped on either side – a pattern noted within other buildings on site – so it is possible Twenty-Eight suffered a partial collapse.

In addition, the earliest known feature in the eastern end of Trench P is the “mega drain”, which runs over 30 metres – from outside Structure Twelve’s south-western corner all the way to, and under, Structure Ten.

Over 0.5 metres wide, the trench-spanning drain ran beneath Twenty-Eight and was partly responsible for pockets of subsidence in and around Structure Twelve. Whether the path of the drain caused similar structural problems with Structures Twenty-Four and Twenty-Eight remains to be seen.

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

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, voids potentially relating to “mega drain”, and assorted masonry.

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.

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

What the situation revealed beneath Twelve reinforces is 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.

A large part of Twenty-Eight’s northern wall was re-used as the foundation for Twelve’s internal wall, while other wall 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.

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.