Ancient monuments: protect and survive. Or not?

General warning: this post constitutes some unusually early thoughts and may be neither accurate, reasonable nor fair. But please read on. And let me know if I’m wrong!

This week’s archaeology course lecture – they’re on Fridays, hence #FridaysForThePast (sorry!) – was led by Dr. Rebecca Rennell and, around a series of interesting slides on understanding the erosion of heritage sites on Uist, there was a fascinating discussion within the group on the issue of the extent to which sites close to the coast and subject to erosion can, or should, be protected.

The discussion was with reference to Dun Mhulan (Dun Vulan), a broch site on South Uist of which more in a minute. Brochs were monumental structures erected on coastal locations on the west of Scotland and across the western and northern isles somewhere between 1BC (possibly earlier) and 3AD (possibly later). With a double skin wall, giving space for access to chambers and galleries and to the upper floor(s), they stood perhaps up to 20m tall and were used for – well, we don’t actually know. Smokehouses for preserving food, possibly; as stores, possibly; as defensive structures, unlikely; as symbols of the wealth and organisational ability of a community, quite probably; as waymarkers for those travelling on the highways of the sea – almost certainly although that’s equally very unlikely to have been their major purpose. Here’s a couple of snaps I took precisely ten years ago of probably the best remaining example of a broch, up on Mousa in Shetland, which has been preserved fairly intact. The one on the left shows the broad dimensions and the general setting – those smudged specks at the top are indeed people; the one on the right shows the double skin wall and stairway access (grilles and framing may not be original features):

Aside of a bit of care and maintenance over the centuries, this is not a reconstruction. The reasons why the broch here has survived in such good condition are likely to be several: Mousa is a small, now uninhabited, island located only a short way off the mainland of a small island archipelago (that is the Shetland mainland to the right centre); and, crucially, it’s sheltered by a small hill to the east (the left) and, though it is itself on the west side of Mousa, it is protected (at least from sea surges) by the mainland. Consequently, much of the force of erosion is not focused on the broch itself; and, equally importantly, there are not a lot of people around requiring its stones for their own structures. Both of these are, of course, mutually reinforcing factors.

Here, in comparison, is Dun Mhulan, in a photograph taken by Howard Fenton: and see also, for a bang up-to-date 3D model, that taken by Smilemaker (Simon Davies) just last weekend, following the lecture:

The site transparently doesn’t have Mousa’s advantages. That’s the Atlantic to the right (i.e. the west) and there’s no shelter from the winds, from whichever direction. Erosion hasn’t just knocked things down, it has also created a lot of infill – the stones on the ground at the entrance way (lying at just about twelve o’clock in the picture) actually form the lintel of the main doorway so a lot of the original action is below what is now ground level. The wall on the Atlantic side is a rebuild, buttressed by a concrete apron put in place in the mid-1990s at the same time to provide some support for the site but which, as can be seen from Simon’s 3D model, has already had to be supplemented by gabions not least since the concrete has been cracked – presented with an angled concrete barrier, the Atlantic has simply gone around the sides (illustrating the issue of measures taken with preservation in mind frequently leading to problems somewhere else). Furthermore, brochs were often built on islets – the left hand side of the picture shows what is actually a saltwater lagoon, but this was originally matched by one to the right which has now been lost to the Atlantic – while that is also the sea to the upper right, the site being on a small promontory (the broader location is well illustrated in this shot, which also highlights that the sea at the upper right in the above picture is held back from swamping the lagoon by a thin bar of shingle). Dun Mhulan is extremely open and thus it is extremely jeopardised.

It would thus be a mistake to say that the future for Dun Mhulan is uncertain because, actually, we can be fairly sure that, at some clearly unknowable point in the future, it will be inundated. And perhaps we’re only one major storm away from that eventuality: at Baile Sear, up the coast off North Uist (and the focal point for our field work), the significant hurricane of 2005 saw 50m of coastline lost in one night.

The dilemma facing archaeologists, and the local community, is therefore well encapsulated by Dun Mhulan: it’s one of striking a balance between preservation and excavation. Or, as the professionals say, ‘preservation by record’ since excavation, depending on its precise focus, is likely destroy a site completely but that, in the process, a clear picture will be drawn up of how the site was used and developed. In conjunction with modern technology, preservation by record becomes an issue of how sites can be presented, sometimes reimagined by informed guesswork but used to educate ourselves not only about the building techniques and the creeds of communities in the past, but also how they confronted climate change (much of what we don’t know about brochs centres on why they fell into disuse and were abandoned). Interestingly, key sites can indeed be relocated to places where they can be better preserved and presented – see the example in the previous link about the Meur Burnt Mound, on Sanday in Orkney (also referenced here) – and in support of community heritage (and, let’s be frank, tourism) initiatives.

So, if we cannot protect Dun Mhulan against coastal erosion, rising sea levels and all the rest of the impact that climate change is having, the question remains as to what can be done with it. Legally it is a scheduled monument, which complicates things a little – scheduled status, whose aim is to preserve sites as far as possible in the form in which they passed to us, is extremely important; but, equally, scheduling paradoxically means that action can’t be taken either so that we can learn from sites. Given the level of threat to Dun Mhulan and its general low-key nature (its level of exposure means that interpretation boards, which don’t currently exist, are likely to have extremely short lifespans anyway), as well as the availability of other broch sites, including in the western isles, offering a better representation of shape, form and structure, I do wonder whether our interests might be better served by re-excavating Dun Mhulan (some work was carried out in the 1990s, before the apron was installed), possibly in conjunction with a Meur-type relocation, so as to capture as much information as possible from it so we can learn. Perhaps the site’s major value could lie in telling us more about how these unique and enigmatic buildings were used, how and why they came into being and why they were abandoned. Or, with a nod to the tenets of academic research, at least about how this one particular site was used.

As ever, the availability of resources is likely to play a major role in determining whether this could happen (excavation is of course costly); or whether, by taking no action, we are playing instead a game of risk with our chances of learning. It seems to me that, in the face of coastal erosion our choice when it comes to such exposed sites is either to try and preserve by record; or else being faced with the reality that we haven’t preserved at all.

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