As reported previously, Martin suspects that, in the Iron Age, the broch might have been the focus of the whole Windwick Bay area – an importance that later Iron Age settlement which was built upon the site perhaps sought to exploit.
After the Cairns broch fell out of use and had possibly begun to collapse in on itself, its walls were deliberately pushed into the centre of the structure, filling it with rubble.
The south-eastern entrance was carefully blocked off – creating the “chamber” discovered by the Rev Alexander Goodfellow, Minister of the United Free Church Congregation in South Ronaldsay, in 1901.
But the “destruction” of the roundhouse doesn’t appear to be a simple land clearance – destroying the old to make way for the new. Instead, it is clear that care was taken to include elements of the original structure into the new constructions.
“The second major thing we’ve been doing is working on the souterrain and, in particular, a building that was constructed over the top of the underground chamber,” Martin said.
“We’ve got some evidence for the interior arrangements of the building, with a hearth, upright stone settings and the souterrain entrance built into the floor.
“What we thought was going on here has been proved beyond a shadow of a doubt. The souterrain fits into the structure of the broch like a hand in a glove, and there’s no doubt in my mind that the broch’s entrance passage was deliberately included into the souterrain to be used as its inner chamber.
“The decision to reuse the broch entrance was intentional, and seems to have been in some way significant — it was not just the expedient use of a convenient space.
“Basically, at the point where the souterrain was being constructed it was very, very close to the time that the broch itself had been abandoned. They had deliberately filled in the interior and exterior spaces of the broch, mounding up material on the outside of the structure, essentially turning what had been a freestanding building into a large mound.
“Just one feature of the original broch remained accessible within that mound – the entrance passage that had now been incorporated within the souterrain.
“To these people, I suspect the past is a domain hidden in mounds and knowes. I think that many an Iron Age person was acutely aware of ruins — ruins that were already ancient to them — inside these mounds. Were they attempting to create a link to those that had gone before? It’s entirely possible that they extended the sense of the ancient to ‘their own’ remains.
“Like the nearby Windwick earth-house, access was through a hole in the floor. At The Cairns we found a stone setting overlain with two rotary querns which had been broken, but the pivot holes were directly over a gap in the entrance.
“You can’t help wondering if that’s been used for pouring substances into the souterrain, so one of things we’re going to do eventually is chemically test floor deposits from directly beneath to see if we can pick up any trace of what might have been poured in there — if that is indeed what was happening — whether it was libations or something more ‘practical’.
“The souterrain, and the above-ground building associated with it, are definitely post-broch, and whereas before I thought that probably meant it was quite a late souterrain, now the upper deposits from the broch interior are hinting at quite an early occupation.
“This means that the end of our broch is some centuries earlier than has often been encountered elsewhere. And, if that’s the case, it may well bring the souterrain back into an earlier stage as well. It may even be Middle Iron Age — just later than the broch, first or second century AD, perhaps.”
The early date for the broch and subsequent earth-house appears to be borne out by a discovery made last year, although Martin stressed it can’t be used as definitive dating evidence.
He explained: “One find we had out of the fill last year, from the unroofed, broken-up part of the souterrain, was a whale-tooth pommel from something like a sword or dagger.
“An artefact like this would usually be slotted into a first century AD-BC date range. Now, although this had been incorporated into the infill so can’t be used to date the souterrain, I’ve got a feeling that it’s another piece of circumstantial evidence that suggests the structure is, in fact, much earlier than we once thought.
“Increasingly, we’ve got this concept that there’s actually more human bone associated with souterrains than had formerly been appreciated.
“From the souterrain chamber, we’ve recovered one piece of bone. It’s badly preserved, but it may be a human ulna. And then, when we look at the Rev Goodfellow’s scant account of his 1901 foray into the mound, he said that he encountered two fragments of human bone.
“But although we appear to have human remains from the chamber, that doesn’t, I think, mean that these were necessarily sepulchral monuments – I don’t believe they are tombs in any shape or form – but the fact that they’re using bits of people as ‘artefacts’ is very telling of the significance of this souterrain.
“I think, in this case, it’s all about regulating and controlling access to these ancient remains of the broch itself.
“I can’t help feeling that was of a very high importance to them — rigidly and strictly controlling access to these ancient remains. The simple fact of the matter is, just as today, whoever controls the interpretation of the past is able to present the orthodoxy of the present and thereby dominate the future. It’s a political thing, as well as a ritual thing.”
In the case of The Cairns earth-house, Martin believes that the structure’s close relationship with the broch reflects its builders’ interest, or connection, to the site. Whereas there are other examples of earth-houses being built into earlier sites, particularly Neolithic, Martin wonders whether The Cairns souterrain is linking to the community’s more recent past — perhaps even to the original inhabitants themselves.
“It may well be that some of the individuals associated with the broch, centuries before the souterrain, were even then still just within the ken of social memory and local knowledge, and there was a genealogical understanding of some of the people associated with that broch.”
But this link was not to last.
In the later Iron Age, the roof slabs were ripped off, the chamber filled in and the majority of the roof lintels broken up. Then, after the broch entrance had been filled in, fragments of the broken lintels were used to block off access.
“However many generations it was after the construction of the souterrain, they were very emphatically breaking it up, with, I have to say, a fair degree of violence. It’s clear that, at this point, they were no longer going to be accessing the chamber and former broch building in the same manner.
“It’s from this stage that we start seeing the ‘bites’ being taken out of the broch, as later builders came in and began adding structures to the site. But what we’re seeing is that they were still paying some semblance of respect to the original structure, or at the very least accommodating the remains of the broch — but it’s in a different way. The strict, rigid control in place during the time of the souterrain was gone and more numerous buildings start crowding over the broch.”