Excavation Iron Age ORCA Swartigill

Archaeologists resume excavation at Caithness Iron Age site next week

On August 23, 2021 archaeologists from the UHI Archaeology Institute, aided by volunteers, will return to the Burn of Swartigill Iron Age site in Caithness. Ahead of the 2021 excavation season, Rick Bartongives us an update on the project so far.

Next Monday, August 23, archaeologists from the University of the Highlands and Islands Archaeology Institute, aided by volunteers, will return to the Burn of Swartigill Iron Age site in Caithness.

Ahead of the 2021 excavation season, Rick Barton, from ORCA, gives an update on the project so far:

We are preparing for another season of excavation at the Burn of Swartigill and we are all very excited at the prospect of getting back on to the site! Now is the ideal time to have a recap of the project and keep you up to date on what we know about the site so far.

The site was first investigated by members of the Yarrows Heritage Trust and CFA Archaeology in 2004. Members of the trust had noticed some structures eroding out of bank of the burn.

In 2012, concerned that the burn in spate could wash away valuable archaeological evidence, the Heritage Trust recorded the eroding section. They discovered the remains of structures and deposits containing ceramics, which appeared to be Iron Age in form.

In 2014, ORCA Archaeology undertook a geophysical survey of the site combining magnetometry, earth resistance and ground penetrating radar. This survey confirmed the likely presence of substantial structures and evidence of occupation at the Site.

ORCA returned in 2015 to do some small exploratory work and the excavation has continued to expand from there. In four seasons of excavation the team, including professional archaeologists, local community volunteers and students, have uncovered the remains at least four buildings.

One of these buildings takes the form of a long, paved passage. This structure is almost certainly a souterrain, a type of subterranean structure which we associate with Iron Age settlements in Scotland, but variations of these architectural forms are also found elsewhere, including Ireland, Cornwall, Brittany and even Denmark.

View of the Burn of Swartigill site, with the souterrain in the foreground.

There is a great deal of debate between scholars about what these structures were used for, from storage of foodstuffs and materials, to refuges against marauding attackers.

Recent studies, particularly in the Northern Isles of Scotland, points to a little more complexity and highlights possible varied use across different regions and period. There is growing consensus among some archaeologists that these structures are ideologically or ritually significant places within the Iron Age societies that build them.

For more information and discussion around Souterrains, why not check out Martin Carruthers’s piece on the subject.

The centre of the site is dominated by a large oval structure, which looks to have been squeezed into the spaces between multiple other buildings.

Floor surfaces in the central building beginning to be exposed.

Having carefully removed several layers of rubble from within this building, we are starting to see tantalizing glimpses of its form and evidence for occupation layers. The evidence we can recover from these traces of ancient floor surfaces can tell us much about how the space was used, as well as information about what life was like at Swartigill during the Iron Age.

Does this building represent a domestic house? Or has there been some more specialised activities such as metal working? We will find out.

At the edges of the site, we are seeing the traces of further substantial buildings and we plan to start investigating the extent of these in our excavations this year.

These buildings include some very interesting architectural features, such as these edge set “ripple” stones, which have the traces of an ancient river or lake bed fossilised on its surface.

“Ripple” stone from an emerging structure on the site.

Finds from the site include Iron Age pottery and stone tools, mainly comprising hammer stones and pounders. These are simple stone tools probably used for dressing building stone, grinding substances for various processes as well as food production.

We have also found several quernstones which are used for the grinding of grain. Samples taken from some of the deposits on site contain hulless barley, an ancient form of cereal crop that was commonly cultivated during prehistoric periods.

The finds also include more specialised tools, like hone stones, which have been used for the shaping and sharpening of metal-bladed tools.

Fragment of lignite bracelet.

We have also found items of adornment, including a fragment of lignite bracelet.

Lignite is a form of canal coal, which can be found in numerous regions of Scotland, and is commonly used in the production of rings and bangles.


The 2021 excavations begin on Monday, August 23, and run until Wednesday, September 15.

The site is located near Thrumster, a few miles south of Wick. To get to the excavation, you need to take the Haster and Tannach road from Thrumster and look out for our signs just before the bridge crossing at the Burn of Swartigill.

There is limited parking at the roadside, so be cautious as you get in and out of your vehicles. The dig is a short hike across boggy moorland.

Visitors are welcome. Tours are available and archaeologists will be on site every day between August 23 and September 1. The excavation will then continue from Monday, September 6, until Wednesday, September 15.

Anyone interested in volunteering on site should email Enquiries.ORCA@uhi.ac.uk for more information.