Cairn Merk

ND15 9 CARN NA MAIRG ('Cairn Merk', 'Westerdale 1')

ND/1331 5103 (visited 14/7/63, 12/7/85 and 4/8/02)

Partially excavated broch, probably solid-based, on flat moorland in Halkirk, Caithness, and next to the river Thurso; it stands on a flat artificial platform and is surrounded by a damp ditch which seems originally to have been connected with the river at each end, forming a moat. The site is a conspicuous mound and has been explored by a long trench on the south-east side which runs from the outer end of the entrance to the inner face of the outer wall. From about 3.30 to 5 o’clock the outer wallface has been cleared of debris and exposed, and a section of the upper intra-mural gallery above this has also been cleared out for about half of this length. This was all done after the Commission’s visit in 1910 and the author was told in 1963 that Mr Murray Threipland, the then landowner, did the work about six years earlier (the remains of the neatly cut trenches indicate some familiarity with modern archaeological techniques). Spoil heaps from his clearances are marked on Swanson's plan beyond the ditch [3].

The broch stands a few feet above the surrounding flat moorland on what seems to be a raised artificial platform; this has a masonry wall running round its perimeter so that there is a flat terrace between the broch and the edge of the platform. A ditch 6.7m (22ft) wide surrounds the mound, ending at the river bank; it was probably originally a moat filled by the river, and – even though obviously nearly full with silt – is still apparently flooded when the river is high. Swanson reports modern drainage ditches leading from each end of the old ditch to the river [3]. There are no signs of an outer bank.

Three narrow stone causeways cross the moat – a feature not known elsewhere. One of them is in line with the entrance on the south-east and seems to be older than the rest, being low and turf-covered; if it is of Iron Age date it should have an opening in its lower part to let the water of the moat through. The other two causeways have vertical sides of drystone masonry and are on the north-east side. They are usually described as modern and Swanson suggests that they were built by Murray Threipland to help remove excavated stone from the site [3]. This seems highly probable.

The main entrance is on the south-east and the outer and inner ends were already partly exposed in 1910 so that its lintels could be seen [2]. Although the Commission stated that the outer one had gone [2] they all seem to be in position now so the front one may have been replaced. The Commission gives the entrance a length of 3.20m (10ft 6in) but the wall nearby is now more exposed because of the trench dug in the 1950s and can be seen to be nearer 3.6m (12ft) thick, taking into account the visible batter on the outer face. The width of the passage is 1.0m (3ft 4in) at the outside, and there are no visible signs of door-checks or of a guard cell. Rubble fills the passage now, apparently blocking it to a greater extent than in 1910 when 2.4m (8ft) of lintelled roof was visible [2]. No guard chamber or door-checks were exposed then and none are now. Also exposed by the recent excavations was a secondary outward extension of the entrance in the form of a passage containing door-checks.

Another recent, and wider, trench has been dug some distance anti-clockwise from the entrance, running from the outer rampart – exposing its inner face – up to the broch wall – where the battered outer face is exposed – and over the wallhead itself. There it has exposed a short length of a mural gallery 60cm (2ft) deep. This latter must be the first tier of what was once a series of raised galleries on top of a solid wall base. There is no sign of its floor being of lintels, which would be the case if there was a ground level gallery below.

The space between the outer wall and the mound is about 9.0m (30ft) across and there are signs of outbuildings under the turf [3, plan].

The whole site is an exceptionally interesting one in that it provides a typical example of a Caithness broch on its own mound surrounded by wall and ditch and with a presumably secondary settlement clustered around it, the whole now in complete isolation and relatively un-disturbed. It also shows how easily a true hollow-walled broch can be detected in this area with a trench over the wallhead. The height of the base of this gallery must be at about the level of the roof of the entrance – that is about 2.0m above the Iron Age floor; this is a lot less than the wallhead at Crosskirk (ND07 2) where no Level 2 gallery was found. The surrounding waterlogged ditch should offer an unusual opportunity for recovering organic remains and the peat-covered flat land round about might conceal an Iron Age field system. The site is one of the most promising in Caithness and well worthy of a full-scale excavation.

Sources: 1. NMRS site no. ND 15 SW 22: 2. RCAHMS 1911b, 33, no. 105: 3. Swanson (ms) 1985, 672-75 and plan.

E W MacKie 2007

ND 1332 5103 A detailed survey was carried out of Carn Ma Mairg broch (Canmore ID: 8358), also referred to as Cairn Merk, as part of the planning condition for the Achlaclan Wind Farm, Caithness, and took place on 31 October to 1 November 2018.

The broch is built on a slightly elevated platform on the east bank of the river Thurso and is enclosed by a ditch that runs into the river at both ends. It has an outer courtyard that appears to run around the entire broch and an external passage leading up to the entrance to the SE. The surveyed profile indicates that the walls survive to a height of some 4m above the original ground surface.

Archive: NRHE (intended)

Funder: Achlachlan Wind Farm LLP

Magnar Dalland - Headland Archaeology (UK) Ltd

(Source: DES Vol 20)