The architecture at Tresness: some preliminary thoughts on the 2021 season
Our previous work at Tresness, especially in 2019, had indicated that we were dealing with a very well-preserved stalled cairn, albeit one that had been significantly altered in parts in the early Bronze Age. In 2019 we revealed a stalled cairn divided into at least five separate cells or compartments. The southernmost cell is partly eroded into the sea, but we think this was the final cell at this end of the monument, although we will never know for sure. The 2019 season had also revealed the hitherto unknown presence of a passage leading from cell 4 out towards the east. This was unexpected, and while it is paralleled at Unstan it is not a particularly common occurrence amongst the Orcadian stalled cairns. Many questions remained, however, for the 2021 season. A key question was the contents of these different cells, and we won’t know the outcome of our excavations of the chamber and passage for a while as material is still being sorted in post-excavation. We can, however, start to say something about the architecture of the monument.
- Was this a single phase stalled cairn or was there evidence for phasing?
There are notable differences in the size of the stones used in the walling of cells 1-3 at Tresness and those in cells 4 and 5. In combination with a distinctly different alignment of these two different parts of the chamber we had suggested that perhaps Tresness was built in two separate phases. The first, we suggested, was a smaller ‘tripartite’ monument, perhaps set within a round cairn as evidenced elsewhere in northern Scotland. We wondered if at some later date the monument had been substantially modified with the addition of cells 4 and 5, the passage and a long cairn. Our excavations in 2021 have not supported this suggestion. Instead, while it seems that the monument may have been built in sections, these do not relate to our previous suggested sequence. We have found no evidence for an earlier cairn, either round or long, and if it was present no trace now remains. We suggest instead that this was actually built as a unitary monument, with 5 cells and a passage, and set within a long cairn. We now need to rethink what the different architecture elements may represent.
- What happened at Tresness prior to construction?
Pre-cairn activity is a well-reported phenomenon at many other monumental sites, and we had wondered if there was activity at Tresness before the cairn was built. If there was we found no evidence for it, although we only investigated one area. Instead it appears that the chambered tomb was built directly on the land surface, possibly with the turf still in place. It may have been positioned in a small clearing therefore, and micromorphology may enhance our understanding of this aspect of the monument.
- What exactly happened to the monument in the early Bronze Age?
We now have a really good understanding of the extent to which the monument was altered in the Bronze Age. We had seen elements of this in the 2019 season, but revealed much more in this season. We knew that people in the Bronze Age had removed the substantial stony backfill to both rob out two of the orthostats from cell 3 to then create and insert a cist in cell 1. We also knew that they had significantly slighted the orthostats at the northern end of cell 5 in order to lay down a wall or kerb for the round cairn they erected over Tresness. The 2021 season revealed in much more detail the extent of the alterations to the overall monument. They had significantly robbed out and repositioned much cairn material, taking away stones from the stalled cairns and using them as part of their round cairn. In addition, some very large stones were acquired from elsewhere to make a large and impressive outer wall or kerb to the round cairn. The reshaping of Tresness was now a minor affair, but a major remodelling. The Bronze Age cairn would have been really impressive.
Links to 3D models