Structures Twenty-Eight, Twenty-Three and Thirty-Three
Around 12 metres long and 8.6m wide, Structure Twenty-Eight was smaller that its successor and sat slightly askew to its north-north-east/south-south-west orientation.
The interior measured c8.7m by 5.5m but as yet we have not revealed any internal fixtures. A ridge running across the floor of Structure Twelve suggests Twenty-Eight had at least one pair of opposed stone pairs, but an apparent lack of corner buttresses could be an indicator that there were more.
Although it shares elements of construction with Structures One and Twelve, architecturally Structure Twenty-Eight stands out as a masterpiece in stone – the finest example of Neolithic construction in the south-eastern section of Trench P. It earns this accolade not just for the superb quality of the masonry but the effort that went into selecting and sourcing materials that went above and beyond the purely practical.
The building’s inner wall face, for example, was built from a fine flagstone with a distinctive pink surface. Glacial striations on these blocks confirms the stone was quarried in Orkney’s West Mainland, perhaps from the Ness of Brodgar isthmus itself.
The quality of Structure Twenty-Eight’s build and finish suggests it was used as a model for the construction of Structure Twelve – and it was definitely a source of building material.
To date, the pinkish flagstone has only been found in Structures Twenty-Eight, Twelve and Twenty-Six and we have no doubt that stone from Twenty-Eight was re-used to construct Twelve, which was subsequently robbed to build Twenty-Six.
On current evidence, it seems there was little or no delay between the demolition of Structure Twenty-Eight and the construction of Structure Twelve. We don’t yet know why Twenty-Eight was dismantled.
It may be that, like many buildings on site, it suffered from structural instability. Or perhaps a new generation wanted to create something larger and more impressive than the building raised by their forebears.
Whatever the reason, Structure Twenty-Eight was carefully dismantled and a large, level platform created by filling in the interior space – a platform ready for Structure Twelve.
To the east of Twenty-Eight, and probably contemporary with it, is Structure Thirty-Three – a building only represented so far by a single, curving wall.
The northern section of this building was truncated by the construction of Structure Ten around 2900BC, although traces may remain beneath the outer paving (pictured above).
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 foundation fragments of numerous constructions, we know little about it.
The curvature of the wall fragment suggests Twenty-Three may be on a par, size-wise, with Structures Seventeen and Eighteen, but this, nor its orientation is by any means certain.
Structure Twenty-Three’s wall curves towards Thirty-Three, to the east of Structure Twenty-Eight, suggesting the two could not be contemporary. The fact the remains of Thirty-Three were truncated by the construction of Structure Ten hints that it might have been later.
At the closest point, Structures Twenty-Eight and Twenty-Three were a mere 85 centimetres apart, creating a small, narrow passage that was extensively marked with incised decoration.