Three-week internship examining the Ness of Brodgar’s stone discs

By Maria van de Fliert

I am an archaeology undergraduate student at Leiden University in the Netherlands. Visiting the Ness of Brodgar some 15 years ago inspired me to study archaeology, and this dream took off in 2022.

In January, I was given the opportunity by Nick Card and Anne Mitchell to do a three-week internship studying the stone disc collection at the Ness of Brodgar.

The collection of stone discs found at the Ness of Brodgar is one of the biggest in the world, yet a true understanding of their purpose has proven difficult. Many interpretations have been offered so far; from pot lids to structural elements and from personal adornments to ritual objects depicting celestial bodies.

To contribute to this discussion, I analysed and photographed 223 pieces and recorded data such as find numbers, trenches, structure numbers, and find contexts. I measured their diameters and thickness, confirming a wide variety of shapes, sizes and completeness.

Some examples:

Analysing the findings, three stages of completeness are most prevalent: 25 per cent, 50 per cent and 100 per cent. Diameters range from four to 48 centimetres; the most common size is around ten centimetres. The overall thickness also shows great variety and varies from just under 0.5 centimetres to 2.6 cm, the most common thickness measured is 9 mm. The type of rock used is predominantly shale, although mudstone was also detected.

One of the main research questions for this internship and final bachelor thesis is to explore the find contexts of the stone discs at the Ness of Brodgar. Because the Ness has a very complex stratigraphy and many events of use, re-use, collapse, rebuilding, extensions, etc., and the limitations of this study it was decided to break the overall history of the Ness into only three major phases:

• Phase 1: pre circa 3200 cal BC
• Phase 2: 3200 – 2900 cal BC
• Phase 3: 2900 – 2400 cal BC

The different phases roughly correspond with changes in building and pottery styles.

Phase 1 is characterised by the early Neolithic style, with orthostats dividing the interior. Unlike the later structures, the roof of Structure Five was supported by large, vertical posts with no evidence of stone tiles.

Phase 2 In sharp contrast to Phase 1 a more refined style of architecture appears which is more angular and symmetrical. This is characterised by pairs of opposed stone-built piers creating recesses along internal wall faces, and corner buttressing. 

This phase includes both the earlier, smaller piered buildings like Structures Seventeen, Eighteen and Twenty-Eight, and the later primary phases of the later larger ones like Structures One, Eight and Twelve. Some of the modifications/ remodeling in some of the buildings falls within this phase. Roofing of these piered structures sees the introduction of stone tiled roofs. The interior plans of these buildings are cruciform or multi-cruciform in plan and can be seen as an elongation, or multiple units, of the single house form, seen in the earlier houses forms at Skara Brae (Clarke 1976) and at the Barnhouse settlement, with recesses built into the walls and the use of single, rather than paired piers to separate spatial elements. The closest direct parallel is House Two at the Barnhouse settlement (Richards 2005).

Phase 3 is dominated by the construction of Structure Ten, which is a total departure in architectural style from the piered buildings. Initially it is similar in internal plan to the later houses at Skara Brae with a square central chamber, internal rounded corners, and a single central hearth, but is built on a monumental scale with walls over four metres thick, an external paved pathway and a large forecourt incorporating at least one standing stone. 

A secondary phase, after a major collapse, sees the remodeling of the central chamber with the addition of internal corner buttressing. Phase 3 also includes the latest remodeled phases of some of the piered structures and the construction of smaller satellite buildings such as Structure Twenty-Six. Although the final use of the interior of Structure Ten occurs around 2500 cal BC, its ruins still act as a focus for Neolithic activity when around 2400 calBC its final demise/decommissioning is marked by the major deposition of cattle remains around its perimeter (Card, 2024).

The overall distribution of stone discs, in combination with the simplified phasing, shows a clear distinction between Trench J and the other trenches, as Trench J is the only area where early Neolithic buildings have so far been identified.

Trench P shows a majority of phase 3 finds and some phase 2 finds in Structures One, Eight, Twelve and Fourteen. Structure Ten has the most finds in total (49 stone discs) all from phase 3. Trenches T, L and N all have one or more phase 3 find while Trench R has a single phase 2 disc.

This preliminary analysis of the contexts has shown that the majority of finds were from phase 3 (178 of 223 discs) but this does not necessarily mean they were all manufactured and used at this time. Many of these stone discs could have been re-used and discarded multiple times. I will be refining this analysis in the next couple of months.

The million-dollar question is of course how and why the stone discs were used. Over the years, there have been many interpretations to make sense of these artefacts.

Were they pot lids?

Stone discs seem to be often thought of as pot lids, as was first suggested by Vere Gordon Childe reporting on his work on Skara Brae (Childe, 1931, p. 51). However, evidence for this interpretation is rare.

Recent excavations in Orkney and beyond echo Childe’s interpretations, e.g. 23 stone discs were found at the Links of Noltland in Westray and were categorised as pot lids, assuming they were used to cover pots in storage. Few showed signs of heating (Moore & Wilson, 2011, p. 100).

Crossiecrown, however, produced seven out of 30 stone discs that showed clearer signs of being affected by heat. Found in floor and hearth contexts, the red and black discolouration points towards them being used as lids while the pots were in the fire (Clarke, 2016, pp. 457, 463).

At the Ness of Brodgar, initial macroanalysis has yielded only two pieces that show potential signs of heating, however, future microscopic analysis may reveal more as red and black discolouration has been found on other pieces.

16865 and 16869 have potentially been heat treated.

But why go through all the trouble of creating a circular object if any flat stone would cover your pot? Or when making a clay pot, why not make a lid too?

In any case, at the Ness most pottery was found near Structure Twelve (5,224 sherds), whereas the stone discs were most abundant around Structure Ten, where “only” 1,456 pottery pieces were excavated. This does not point towards a clear association between pot and disc.

Other interpretations

Not all stone discs are perfectly round, some larger pieces display straight or rectangular elements which could potentially have been used as fillers for rounded walls. Some of the smaller and intricately made discs could have been used as jewellery or adornment sewn into garments (Clarke, 2020, p. 231 and Edwards, 2012, p. 59).

Only a couple of weeks ago, Iversen et al., (2025) published their research on the sun stones from the island Bornholm in Denmark. Archaeologists have found more than 600 whole and fragmented parts of stone discs, many of them with intricate decoration.

The patterns found on the discs, or plaques, are suggested to represent sun and plant motifs suggesting they could have been used as offerings in times of climate crisis. The dating of the discs ± 2900 BCE corresponds with a cooling period that must have had a dramatic effect on the people of the time.

At the Ness of Brodgar, only one disc is known for its decoration, SF 2550 shows the ‘Brodgar Butterfly’ motif.

Could the stone discs of the Ness have a symbolic meaning? Although only one stone disc depicts the Brodgar Butterfly, the zigzags, lozenges and chevrons are common for decorations found at the Ness of Brodgar (Thomas, 2020, p. 139). And even though the other 222 stone discs do not seem to have any decoration (or it was lost due to delamination), they could still have had some deeper meaning for the people making them. Iversen et al., (2025) mention that 38 pieces were blank, which could have been intentional.

Attaching a deeper meaning to decorated or undecorated discs, however, is complicated. Dr Antonia Thomas illustrates this by making us think about our own lives and how items can have multiple functions or meanings ranging from completely arbitrary to deeply profound. The key lies in a meticulous approach and a focus on context (2020, p. 143).

Which brings me to the fact that I will be spending the next few months writing my bachelor’s thesis and trying to understand more about the contexts and possible interpretations of the stone disc collection. I’m very grateful to Nick Card, Anne Mitchell, Mark Edmonds, Paul Durdin, Gary Lloyd, Martha Johnson and Jan Blatchford for their input and I’m looking forward to sharing more insights in the near future.

References

• Card, N. (2024, May 16). RE: Phasing for Acid Extraction overview paper [Personal communication].
• Childe, V. G. (1931). Skara Brae: a ‘Stone Age’ village in Orkney. Antiquity, 5(17), 47-59.
• Clarke, A. (2020). Stone tools from Ness of Brodgar. In N. Card, M. Edmonds, & A. Mitchell, (Eds.), The Ness of Brodgar, As It Stands. (pp. 224 – 243). Kirkwall, The Orcadian.
• Clarke, A. (2016). The coarse stone from Neolithic sites around the Bay of Firth: Stonehall, Wideford Hill, Crossiecrown, Knowes of Trotty and Brae of Smerquoy. In C. Richards & R. Jones, (Eds.), The development of Neolithic house societies in Orkney: investigations in the Bay of Firth, Mainland, Orkney (1994-2014). (pp. 445 – 472). Windgather Press. https://doi.org/10.2307/j.ctv13gvg8m.18
• Edwards, Zoe. (2012). Stone discs of the fourth and third millennia BC in Britain, [unpublished Bachelor dissertation Bournemouth University]. Bournemouth University.
• Iversen, R., Nielsen, P. O., Sørensen, L. V., Svensson, A., Steffensen, J. P., Land, A., Thorsen, M. S., & Nielsen, F. O. S. (2025). Sun stones and the darkened sun: Neolithic miniature art from the island of Bornholm, Denmark. Antiquity, 1–17. https://doi.org/10.15184/aqy.2024.217
• Moore, H. & Wilson,G. (2011). Shifting Sands, Links of Noltland, Westray: Interim report on Neolithic and Bronze Age Excavations, 2007—2009 (Archaeology Report, 4). Historic Scotland.
• Thomas, A. (2020). Art in context: the decorated stone assemblage. In N. Card, M. Edmonds, & A. Mitchell, (Eds.), The Ness of Brodgar, As It Stands. (pp. 132 – 149). Kirkwall, The Orcadian.