Cnoc Tigh and Tarlogie Dun Excavations (Iron Age Round Houses)

by David Findlay (NOSAS)

These excavations, in April and July 2014, were led by Candy Hatherley and form part of the University of Aberdeen Northern Picts Project. Cnoc Tigh (see also our earlier blog entry) and Tarlogie Dun are Iron Age round houses situated on the north coast of the Tarbat Peninsula in Easter Ross. They are both on the high ground about 200m back from the coast giving them spectacular views across the Dornoch Firth to Sutherland and up the Sutherland coast. Neither site is naturally defensive and, though both have watercourses to one side creating a gorge and a steep bank to the sea on another side, that still leaves two sides open to the surrounding countryside.

The NOSAS team at Tarlogie, looking N (David Findlay)

They differ from the three duns excavated by the Aberdeen University Team in 2013 in that these were all on the south side of the Tarbat Peninsular and were relatively defensible due to the natural features, although Tarrel is overlooked by the cliff on the landward side.

Both Cnoc Tigh and Tarlogie appear to date from about 400 BC with occupation at Tarlogie lasting for 800 years to about 400AD. I do not know of any dates yet for the latest occupancy at Cnoc Tigh although I understand that suitable charcoal samples have been taken for dating.

The 2014 excavations at both sites reveal severely robbed and damaged stone walls; there are discernible facing walls in a few locations but largely only the fill remains. Both sites show a lot of evidence of the structures changing with time.

Excavations on the Tarbat Peninsula: Scotsburn (Iron Age Broch or Dun) Part 2

By Vaidutis Žutautas (University of Aberdeen)

Just above the left bank of steep wooded ravine of the Balnagown river, remnants of a prehistoric dun (NH77NW 6, NH 7148 7616) sit on the sloped eminence surrounded by a complex of structural features, arguably belonging to it. The site has been known for a long time, as it still stands prominently and it is likely that it has not been disturbed by agricultural activities throughout centuries, although some possible robber trenches can be seen on the E side of the dun wall. Prevailing arguments suggesting that the roundhouse could carry the title of ‘a broch’ were usually subjected to narrow over-surface interpretations by only taking into consideration structural features such as the diameter of the house (13m), wall thickness (~6m on the surface) and its elaborate compounds that skirt the dun. However no comprehensive evaluation has been done since 1968 when OS did a basic descriptive survey and designated the structure as a dun.

In order to expand the distributional scope of the late prehistoric structures in Tarbat peninsula and its environs, the team of archaeologists from the Aberdeen of University has targeted Scotsburn Dun in seeking to evaluate the underlying archaeology. A permission to locate 3m x 20m trench and extract effective dating material that would provide a chronological framework for the site was given by Historic Scotland Scheduled Monument Consent. Additionally, to answer perhaps the most intriguing question­- whether the structure is a broch or a complex dun – authorisation was given to uncover the roundhouse wall and identify its external morphology that would allow drawing assumptions regarding its structural classification.

Since this excavation was ongoing along other two digs in the area (Cnoc Tigh and Tarlogie Dun), the logistics were relatively subordinate especially in terms of people on the site. At least two archaeologists were working at Scotsburn with a kind help from volunteers living in the region. Yet even said that, the dig has not been crowded and therefore dealing with exceptionally complex archaeology and nearly 40m³ of deposited rubble extended original ten day dig to a four and a half week mattocking paradise.

Realising the complexity of the site on the first day, it was decided to open 2m x 20m trench stretching NW-SE encompassing area between the roundhouse and the enclosure wall and another two earthworks giving another 6,8m extension for vegetation, top soil and limited latest collapse deposit clearance from the dun wall. Unsurprisingly, it has been a highly demanding task to define structural features and reach occupation horizons by removing tons of collapsed stones; this process took nearly two weeks mainly allocating labour in two areas: a) between the roundhouse wall and the enclosure wall, and b) between the enclosure wall and the first earth bank.

Aerial picture of the entire trench showing mid-excavation.

Excavations on the Tarbat Peninsula: Scotsburn (Iron Age Broch or Dun) Part 1

Mid Excavation Report by Oskar Sveinbjarnason (University of Aberdeen)

The excavation at Scotsburn House aims at dating the occupation as well as trying to discern if the site is a broch or a dun.

Outer wall face of Scotsburn “house” with Roland.

A single trench 20m long and 2m wide was placed over the building wall and extends northwards over four rampart banks. The round house wall has been revealed but it has not shown yet if it is a broch or a dun. The ramparts have so far shown a nice stone facing. The site is getting more complex as “new“ walls have been uncovered in the trench. The relationship between these walls and the ramparts and ditches is being investigated.

Photo from the trench with Leaf and James.

The lower left corner of the picture shows one of the banks. Behind Leaf and James is another bank and towards upper right corner is the Scotsburn house wall.

Following Oscar’s report an iron age road surface was uncovered in this ditch.

Excavations on the Tarbat Peninsula: Cnoc Tigh (Iron Age Round House)

by Oskar Sveinbjarnason (University of Aberdeen)

The excavation started as planned on the 22nd June. A 15m long trench and 10m wide was opened over the northern part of the dun. It took 2 days to open up the area (gorse removal and grass) and as the surrounding field was under crop, a JCB was not able to access the site and speed up the opening. It soon became apparent that the site has been largely robbed of stones, likely during the 19th – 20th Century, possibly to make the enclosure which sits on top of the dun. The quarry holes can still be seen. It was a hard task to plan and remove this later enclosure, mainly due to the amount of rubble and the fact that the enclosure was little more than tossed up earth and stone bank (we can firmly assume that this is not the Castle Corbet) and blended in with the dun itself.

Picture showing the surviving outer dun wall. The rubble to the left is a collapse which hid this outer wall face.

In the trench the outer dun wall face was harder to find than we expected and is it due to the large amount of collapse from the dun wall core outwards and collapse from the enclosure on top of it as well. It was towards the end of week 2 when we finally figured out where the outer dun wall was located and which made the site nicer and easier to understand.

The dun wall turned out to be a complex construction with multiple stages of construction now visible. Initially it seems to have started out as a round house with about 1.5m thick wall. Up against this wall, additional 2.5m of extra wall was added, making the wall about 4m thick.