Archaeologists who have a head for heights

A NEW archaeological survey of sea stacs off the Western Isles has uncovered evidence suggesting that the rocky outposts were inhabited from a much earlier period than previously thought, potentially revolutionising current thinking about who used the stacs and why.

Hundreds of sea stacs in varying shape and size protrude above the sea along coast of Lewis, in the Western Isles. Some stacs are joined to the mainland by a rocky promontory, while others are completely surrounded by water. If a fragment of land is wider than its height it is considered to be an island, but otherwise it is a stac.Using the appropriately titled abbreviation STAC, members of the Severe Terrain Archaeological Campaign test their advanced climbing skills to conquer these sheer cliffs and access hitherto inaccessible sites. Established two years ago, the group uses information collected from oral history and old maps before visiting stacs that once showed signs of previous human habitation.

"You get onto the stacs and have a root around," says field archaeologist Ian McHardy. "We try to understand what's there and also do a detailed map of each stac."

Until now little has been known about the stacs, although they were thought to be predominately Iron Age and used for defence. The Iron Age was certainly a period of conflict, as can be seen by the number of brochs and wheelhouses on Lewis, so it made sense to think that the buildings on the stacs came from this period and were for this purpose. These new findings may change this assumption.

"We found a much bigger range of time period for people using the stacs," confirms McHardy. "On one stac, Dunasbroc, we found high-quality pottery and some beautiful leaf-shaped flint arrowheads. We can't confirm until we get a specialist to analyse the pottery, but it looks like being of late Neolithic period."

This period – between 3,000BC and 2,500 BC – would put the use of the stacs much earlier than previously thought. While exciting in itself, it wasn't the only surprise the STAC members found on Dunasbroc.Along the contour of the walls they uncovered a small platform that showed signs of being repeatedly burnt. Its function is still a mystery, and McHardy finds it easier to say what it wasn't used for.

"It is in the wrong place for a beacon," says McHardy. "Where it is situated would have been hidden by the headland. And it can't be a kiln. Why would anyone want to build a kiln on a hard-to-reach sea stac?"

Which leaves them with a tantalising theory.

"One possibility that we're looking into is that it could have been a cremation pyre," says McHardy. "We know from burial tombs of the same period that they cremated people and this could link the two."

They are awaiting tests on a partially burnt bone fragment found close to the site before they can begin talking about their theory with any confidence. If the bone does prove to be human, then this would add to our knowledge of how people from the Neolithic period ritualised death.Although this summer's survey has proved the most intriguing so far, previous digs have also turned up items and places of interest. In 2003 they looked at Stac Dhomhnuill Chaim in Uig, on the west coast of Lewis, which local history and legend described as the hideout of the outlaw Donald MacAulay. Locals recall the story of him living there for a number of years in the 17th century and on the run from the crown.

The team found the remains of a house and some other buildings which seem to add physical proof to oral tradition and may go some way to confirming the story.

Another stac that stays in McHardy's memory is Stac a Chaisteil. He remembers it not just because of the artefact they found there, but because of the effort involved.

"It was the most difficult to access, we needed to absail down to get to the base and then climb up 30 metres," remembers McHardy. "It took an hour to get on and off every day, but we did find a block house (a precursor to the broch), which is rare in the Western Isles."On Stac a Chaisteil they also found a puzzling altar-like structure which they initially found hard to date. Far from being some incredible pre-Christian artefact it turned out to be a more modern interloper. The altar was placed there in the last 20 to 30 years by a local youth, no doubt keen to show off by scaling the rugged cliffs and leaving behind a permanent reminder of his prowess.

As the first and only project of its kind in Scotland, STAC is opening up a number of different sites for exploration. McHardy enthusiastically points out that there are more places - especially in Shetland and Orkney - that could benefit from an archaeology team who have been trained in rope safety and climbing.

Their eye-opening discoveries can only ensure a bright future for archaeologists in Scotland seeking a bit of adventure.

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