Off the Beaten Track 20 - West Side Crannogs
Published: 13 August 2020
Today’s walk takes in a rather different type of site – a crannog. Crannogs were built during the Iron Age and are generally defined as a type of loch-dwelling. However, confusingly, the term refers to what lies underneath, rather than what was built on top.
Crannogs are holms, or islets, which are partially or totally artificial. In some cases a substantial amount of rock was added to natural outcrop, to make the foundations large enough to accommodate a building. In other cases, the islet was constructed more or less from scratch.
The type of building that the islet housed was not consistent. The reconstruction at the Crannog Centre in Loch Tay, Perthshire, shows a wooden roundhouse – a type of dwelling for which we have never found evidence in Shetland. Here, crannogs were built to accommodate a range of Iron Age buildings: brochs, forts and roundhouses. Some of the sites were reused at a later date, such as for the castle in the Loch of Strom and the Thing site (Norse meeting place) at Tingwall. The excavations at Tingwall surprised the archaeological team because, instead of finding Viking remains, they uncovered an Iron Age roundhouse.
Crannogs were built throughout Scotland, usually in freshwater lochs. In Shetland however, just over half the crannogs were built in coastal waters. Very few have been investigated and most hadn’t even been identified as crannogs until recently. In 2016 Michael Stratigos and Claire Christie looked at the existing records and identified 30 Iron Age islet sites which could be considered to be crannogs. They looked at four examples, in the Central Mainland, below the waterline as well as above. Most had been hiding in plain sight because, understandably, archaeologists usually focus on the building which they can see rather than what lies beneath the waves. In the majority of cases, the sites are well-known as brochs.
This short walk takes you to a crannog on the West Side. To visit Burga Water you will need to find a suitable parking space on the road between the Bridge of Walls and Sandness. There are two sites associated with the loch. For a longer linear walk, continue south for another kilometre to explore the prehistoric and later remains at Trolligerts.
To begin, head west towards the loch to find a promontory projecting into the west side of Burga Water (HU 229 541). 5,000 years ago Neolithic people, the first farmers, thought it was a good place to bury their ancestors. The chambered cairn is just over 10 metres in diameter and 1 metre high.
Continue south and east around the loch to find the crannog which is marked on the Ordnance Survey map as a “dun” (HU 234 540). “Dun” is a word derived from Gaelic, a general word for a fortified place, and is perhaps the equivalent of “burg” or “brough” which is more commonly used in Shetland and is derived from the Norse.
Burga Water has also been described as a broch, but it clearly isn’t a double skinned tower. Most of the islet is enclosed by a stone wall which varies in thickness from 1 - 2.5 metres. This is not wide enough to be the wall of a broch, which would be around 5 metres at ground floor level, and double skinned higher up.
People who have made it onto the island suggest that the amount of tumbled stone implies that the building never stood more than 3 metres high. This isn’t conclusive, since stone may have been removed from the islet for use elsewhere.
Today there are three or four courses of wall visible above the tumble, and it is possible to see the walls of the building from the shore. There is nothing else structural visible from the shore, perhaps due to the long grass which covers the islet. The walls give the impression that the crannog was fortified.
The Ordnance Survey recorders could not identify a causeway between the islet and the shore, but later visitors do seem to have spotted one. It is possible that some of the accounts may have confused the crannog with the adjacent thin island, which seems to have its own causeway. The stone visible on that island also makes it look suspiciously like another potential crannog site.
From Burga Water you can either return back to the road or, if you are happy to cross fences, carry on southeast across the moorland, roughly parallel with the road, for about a kilometre to find the extensive prehistoric settlement at Trolligarts.
Trolligarts (centred HU 245 524)
As you walk, you will notice that you are crossing the remains of numerous field walls which may have belonged to the prehistoric farm at Trolligerts. These increase in density as you get closer to the settlement. The whole slope of the hill is scattered with cairns of field-cleared stones, and a number of enclosures defined as low tumbled walls make up a pattern of irregular prehistoric fields. These field walls appear and disappear under the peat which has formed during the 4000 years which have passed since the Neolithic people created this farm.
As you approach the site from the north, one of the first structures you encounter is a chambered cairn (HU 244 524). The cairn is approximately 5 metres in diameter and is roughly circular. It has a kerb of large boulders around the edge. Inside there is a small central chamber, which is also marked out with large boulders. The entrance to the chamber is on the south side.
The heart of the settlement lies another 150 metres to the southeast, just below a rocky knoll, where there is a very large mound of rubble (HU 245 524). This seems to be the remains of either one very large, or possibly as many as four, prehistoric oval houses. It may have begun as a single building which was later divided. Alternatively, it may be a long sequence of houses, one built on top of one another.
It is possible that downsizing to smaller houses, and also living as a group in a village-like collection of houses, may be the result of climate change. A deteriorating climate may have contributed to the increase in peat growth which took place towards the end of Neolithic/ Bronze Age times. Only archaeological excavation can truly untangle this story.
There are numerous smaller mounds around this central group, which might be smaller buildings, perhaps workshops or agricultural buildings. There is also a cluster of four much more recent plantiecrubs and yards in amongst the earlier remains. The crofters made good use of the stone gathered by the Neolithic builders.
At the southern edge of the site, not far from the road, there is another circular cairn (HU 243 522). There are traces of a kerb protruding through the tumble but it is not possible to identify any internal features amongst the stone.
Dr Val Turner, Regional Archaeologist, August 2020
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