A major excavation on a broch-like structure at The Cairns, South Ronaldsay, finished last week – days after the preliminary results of a paleoarcheological survey of the nearby Blows Moss were outlined at the Orkney International Science Festival.
An Iron Age settlement in South Ronaldsay has been the focus of an archaeological dig over the past few weeks.
A short distance from the Windwick souterrain Martin excavated previously, he was drawn to the grassy mound by an anecdotal account from 1901. It explained that the Rev Alexander Goodfellow, Minister of the United Free Church Congregation in South Ronaldsay, came across an underground chamber while digging down into the top of the rubble-filled mound.
Peering into the darkness, Goodfellow saw stone fittings and partitions, extending from the back of the structure, he likened to the stalls in a cattle byre.
The modern excavators have uncovered this chamber – an earth-house typical of the Iron Age – but it is now clear this was just one of a number of buildings built on the site.
Working down through centuries of accumulated rubble, the excavators reached what appears to be the first thing built on the hillside – a massive broch-like building. But although to all intents and purposes it looks like a broch, and appears to be built to the same general design and proportions, it lacks some elements typical of the structures.
Martin said: “We’ve got these incredible, five metre thick, solid walls, with an external diameter of 21.5 metres, forming an inner chamber 11.3 metres in diameter. This makes it bigger than both the brochs at Gurness and Midhowe.
“But although the internal space was much bigger than Gurness, the width of its walls makes me think it might not have been very high. For comparison, it was perhaps as high as the ruins of Gurness stand today. This structure is more like Crosskirk, in Caithness, which is early Iron Age.”
Martin continued: “Built into this wall, in the south-west of the structure, we have a beautiful intra-mural, teardrop-shaped cell. We’ve found charcoal around the entrance of this, as well as lots and lots of round wood, together with whalebone showing evidence of scorching.
Martin has speculated that this could be the remnant of some form of screen that partitioned off the wall chamber. He suggests that it perished in a fire – the form and circumstances of which are not clear.
“Whether the fire was contained in this cell, and was put out, or whether it was later, perhaps after the structure went out of use, I’m not sure,” he said.
Among the finds were huge quantities of unworked whalebone, pottery and an iron knife.
“From the pottery we’ve got, it’s estimated the structure dates from the mid to late Iron Age – perhaps around 500BC, which makes it earlier than the Broch of Gurness. But we can’t say for sure yet because we’ve yet to reach the base of the floor area.”
Outside, a number of “lumps and bumps” could represent buildings clustered around a south-east facing entrance-way – much like the one found at Gurness.
Moving away from the roundhouse, a trench was opened to discover the extent of the surrounding archaeology. And there was plenty of it. However, a rich, dark silty area of soil some distance from the structure could, suggested Martin, represent a filled-in ditch – a ditch that would have encircled the settlement like those commonly found on broch sites. Although this has yet to be fully investigated, there are other hints of typical broch “defences”.
“On the west side of the site we can see an earthwork which could indicate we’ve got ramparts and ditch,” said Martin.
“It’s fairly obvious it must have been a high social status site in the area. At Windwick we had lots of agricultural tools and implements. Up on the Cairns we’ve not. Instead we’ve got the grain processing stuff so maybe there was a division of labour.”
“Also, the amount of whalebone we have here makes us wonder if it’s something that was being controlled. We know from the huge quantities, and the fact the came from different animals, that they were taking in whales regularly. Presumably these were beaching on the shore below, but maybe they were actively going out and hunting them.”
However they were sourcing the whales, it appears that the owners of the roundhouse had some form of claim, or right, to the carcasses.
Copious quantities of red deer remains were also unearthed. From these, it appears that the inhabitants were actively managing the animals – culling and “harvesting” them for their antlers and presumably food.
After the broch-like structure fell out of use, and had started to collapse in on itself, at least one secondary building were built – labelled Structure B by the archaeologists.
“On top of the mound are a series of stalled uprights. Someone came along and cut into the collapsed rubble to erect a structure.
Inside this dwelling are the remains of at least one hearth, with a thick layer of burnt material. Stonework beside an obvious hearth could represent a second hearth or this could be just stands for holding tools, utensils or the like.
Martin explained: “All the evidence so far points to this later structure being domestic, although it might be that it changed function later, from domestic to storage, perhaps.”
Outside, the archaeologists have also found evidence of metalworking in the form of slag and other materials.
While the builders of the rectangular house cut into the rubble and erected their structure in among it, a later construction phase saw a section of the roundhouse’s collapsed masonry cleared away – possible to allow the construction of a second roundhouse in the lee of the “broch” remains. Here, they appear to have been clearing away segments of rubble, before shoring up the face with little stacks of walling.
The last structure on the site was the one that attracted Martin there in the first place – the earth-house.
Again dug into the rubble of the primary building, the souterrain’s construction may have symbolised the end of the site’s use as a dwelling place.
“Normally, a souterrain is the very first thing to appear on these types of site but this one seems to be inserted into the rubble of the earlier broch-like structure,” said Martin.
“As souterrains go, its slightly unusual but there are some that are built into the remains of the big brochs. So you can see them towards the beginning, or towards the end, of a site’s use. In this case it would appear that the souterrain’s construction perhaps marked the end of the site’s life.”
Paralleling the find at nearby Windwick, inside the excavators found a stack of saddle querns and stones. In addition, the entrance passage had been deliberately blocked, presumably at the end of the chamber’s “working life”.
Summing up, Martin said: “It’s a fantastic landscape full of archaeology. There’s tombs, a promontory fort, a treb dyke – a prehistoric earthwork, not to mention the sites at Windwick and here on the Cairns.
“As well as the archaeology, it would be great to do more landscape work around here. The work that Jane Bunting and Michelle Farrell have done in Blows Moss is fantastic and is providing us with a clearer picture of what was going on here at the time these buildings were in use, and before.”
This environmental work, which saw cores taken from the nearby bog, Blows Moss, showed that around 8,000 years ago it was a wooded loch. This woodland decreased throughout the Neolithic and Bronze Age and, by the time of the Cairns roundhouse, would have become much like the mire we know today – although perhaps a little drier.
In the Iron Age, the roundhouse might have been the focus of the area – an importance the later structures perhaps sought to exploit.
However, rather than sitting in the heart of the area’s farmland, Martin feels the house occupied a more peripheral position. He is of the opinion that the broch-like structure sat on the high ground overlooking the arable fields on the south-facing slope, with the hill land behind.
It was meant to impress and to those in the houses in the valley, and working the fields, the structure would have been an imposing sight. Dominating the ridge above them, perhaps it was meant to reinforce the status, wealth and power, of the owners to those working in its shadow.
The excavation was funded by Orkney Islands Council. The excavators would also like to thank landowner Charlie Nicholson.