When is an island not an island? The answer? When it is a crannog.
Crannogs are small, artificial islands found in many of Scotland’s lochs and inland waters. But they are a class of monument not usually associated with Orkney. Is this because there is a lack of them? Or simply because they have gone unnoticed or been ignored for centuries?
From the shore, most crannogs look like rocky mounds or low, grassy islets, accessible to only the most dedicated explorer. This inaccessibility may be part of the reason Orkney’s crannogs have remained firmly in the shadow of the county’s grander monuments.
Although only four or so crannogs listed in the official records, this is now thought to be the tip of the iceberg and this lost chapter in Orkney’s archaeological record is about to take centre stage with a new project in Rousay and at Voy in Sandwick.
At the helm is Bobby Forbes of Stromness-based Sula Diving, who is also one of the team which teaches underwater archaeology for the archaeology masters course at Orkney College.
Taking advice from Orkney Archaeological Trust’s archaeologists, Bobby and his team will spend the next few months examining the aquatic sites in an effort to better understand their place in the landscape and history.
“If you look at most of the islands in Scottish lochs, most are actually man-made and very few are natural. But crannogs are a part of Orkney’s archaeology that’s never been looked at,” he said. “We’re going to do some basic survey work – really just a preliminary ‘look see’ to see how the sites ‘fit in’ and where they come in the vast archaeological timescale of the areas.
“If we can generate enough interest in this, I hope we can expand the work to get a better view of the entire loch and the area surrounding it. For example, a paleoarchaeological core of the loch bottom to see how the Stenness Loch itself has changed since glacial times.”
The Wasdale crannog, in Rousay, is perhaps the best known in Orkney, where investigations have uncovered houses from the Pictish period. Another example is found in St Tredwell’s Loch, in Papay.
Crannogs in history
But although little is known or recorded about other crannogs in Orkney, elsewhere in Scotland they are known to date from the Bronze Age right through to the 17th century. Their role also varies, with some incorporating dwellings while others were status symbols, fishing platforms or even refuges.
Agricultural improvements across Scotland over the past two centuries have seen a considerable change in the landscape, with large areas of marshy, or water-logged, land now drained. Prior to these improvements, a crannog was a way of utilising the wetter land for structures that didn’t encroach on to good farming land.
As the climate deteriorated throughout the Bronze Age and into the Iron Age, the resultant decrease in usable land meant that farmland became scarcer and therefore more valuable. This could also have led to a greater reliance on crannogs.
Voy, at the north-western end of the Stenness Loch, is a classic example of a potentially rich archaeological site that has been neglected over the centuries.
Bobby Forbes came across the site while carrying out survey work on the loch for Scottish Natural Heritage. Examining aerial photographs of the loch, he noticed two clearly visible causeways leading out to the two small islets at the end of the loch.
Until the divers get a chance to examine this closely, it is not known whether the skerry-like object is natural or a man-made structure. Whatever it is, it is generally visible only when the water in the loch is low – generally once every fortnight.
Bobby explained: “The interesting thing about the Stenness Loch is that it connected to the sea, and as part of a previous, unrelated study, we looked at the tidal regime of the loch and the adjacent Bay of Ireland.”
“As expected the tides in the bay followed the usual pattern – two tides a day – high and low tide – and varying between spring and neap. But because of the narrow entrance to the loch at the Brig o’ Waithe, what you tend to find is that although you get slight daily tidal fluctuations there’s a build up of water as you go from neap to spring tides. So in the loch there’s actually two tidal cycles superimposed on one another – one that’s the normal daily cycle and one that follows the monthly lunar cycle.
“This means that the causeways to the Voy crannogs are only ever exposed at the very low tides once a fortnight. We thought that this was worth investigating further.”
One of the Voy crannogs, the one nearest the shore, has the remains of the structure on it, with a stone causeway – which is thought to have once been turfed over – leading out to it from the shore. The second islet also has a causeway but it has been badly eroded. There also appears to be no recognisable structures remaining on the island.
But the possible crannogs are not the only points of interest in the area. Further round The Ness, Bobby and his team found an old stone quarry, with some of the stone still wedged up in it, and a boat noust. Neither of these sites are recorded in Orkney’s Sites and Monuments Record.
Bobby said: “What we need to do is detail the area and to some extent to find out where these structures fit into the archaeological record. We know that crannogs have been used since prehistory and right up to the 17th century so we want to fit them into that timeline somewhere and then look see how they relate to the rest of the sites in the area.”
It is also hoped that a team from the Scottish Trust for Underwater Archaeology will also visit the sites as part of an ongoing study of Scotland’s crannogs.
The project has been funded by Orkney Islands Council and Sula Diving.