7.3.5.2 Complex Atlantic Roundhouses / Brochs / Galleried Duns

The terminological debates on broch and Complex Atlantic Roundhouses (cARs) have been simmering for decades (Armit 1992, 2003; MacKie 2002; 2007; Romankiewicz 2009; 2011; 2015; 2016; Cavers et al 2015; Barber 2017). Romankiewicz (2011, 29) defined them as ‘circular, sub-circular or oval stone-walled roundhouses that have evidence for architectural complexity in the form of intramural space and well-coursed masonry’. The key problem with poorly preserved structures is determining whether they had intramural galleries. In some cases these start from upper stories, so without good preservation the defining evidence will be lacking. The distinction between substantial sARs and cARs can therefore seem slight. Some of the sARs were substantial structures. In the past some have been defined as brochs, but without the diagnostic intramural features, they are not considered cARs.

The terminological confusion increases when galleried duns are considered: the presence of intramural features places them in the cAR group, but because generally, but not exclusively, they are of a smaller diameter in size, they are not considered brochs (Graham 1947; Cavers 2010). These galleried duns are also distinct from enclosure duns.

The distribution of cARs and brochs known in the Highland region can be seen on Map 7.3; and details are available in Datasheet 7.3.

John Barber has investigated the structural aspects of brochs with forensic detail, including with experimental archaeology (Cavers et al 2015; Barber 2017; 2018 Rhind lectures), while Tanja Romankiewicz (2011; 2016) has approached the subject from an architectural perspective, looking at design aspects, spatial layouts and structural issues. Both are useful approaches, providing greater insights from simply typological considerations. Romankiewicz (2016; Romankiewicz and Ralston 2020) has highlighted the variety of architectural detail which react to regional environmental circumstances and availability of materials. For example, brochs built in areas that had been substantially deforested, such as Caithness, have smaller internal dimensions, probably due to issues of sourcing timber for roofing and other internal work (Romankiewicz 2016, 18).

Issues regarding broch development and dating as well as the social factors relating to construction have also been the subject of much debate, which is still ongoing (see Armit 2003; MacKie 2007; Cavers et al 2015; Romankiewicz 2011; 2016; Barber 2017). These factors are important for the Highlands, though one should not presuppose one explanation fits all examples. It is therefore important to think about alternatives (Romankiewicz and Ralston 2020 72–73).

The dating of cARs is now seen to begin in the 4th or 3rd century BC with many showing occupation into the early centuries AD, though whether the occupation is continuous or episodic is often debated (Dockrill et al 2006). Dating remains key, as it is probable that every surviving broch was altered and modified either in the Iron Age or later (Barber 2017). Only at Thrumster broch in the Highlands has it been possible to show the chronological changes in detail (Barber and Humphreys 2012).

Heald argues strongly that it is therefore necessary to dig the walls and the interiors to illustrate phasing and re-use, especially since interior remains may relate to re-deposited fill after a structure has gone out of use. For this reason the Clachtoll broch finds are important, because they were sealed by a wall collapse (Case Study Clachtoll Broch). Romankiewicz (2016) also notes that only with large scale excavations will some of the questions relating to the social dimensions of broch building and use be tested. The cost of such investigations is, however, a major factor.

A great deal of work has been undertaken over the years on Highland brochs, on the east and west coasts. These include in Caithness 19th to early 20th century excavations in Caithness by Tress Barry, Rhind, Anderson and Laing (Heald and Barber 2015). Modern investigations of brochs by AOC Archaeology have taken place at Nybster (MHG1593), Whitegate (MHG1645), Keiss Harbour (MHG1659), Keiss Road (MHG1650), Everley (MHG1792) and Thrumster (MHG2043). On the west, MacKie (2007) excavated a number of Wester Ross and Skye brochs in the later 20^th century. AOC Archaeology and Historic Assynt have recently excavated Clachtoll broch in northwest Sutherland (MHG13002). There the preservation was exceptionally good, allowing for a range of detailed analysis, including the study of the spatial distribution of artefacts (Case Study Clachtoll Broch). A number of new, detailed surveys of Highland brochs have also been undertaken in recent years (Cavers et al 2015). 

Several key points have emerged from this work that had provided evidence for the terminology debates and issues relating to the people who built and used the cARs. Most of the sites are multi-phased, and detailed dating is needed.

Some Highland cARs are built on sites that were probably earlier hillforts as accepted in the Atlas of Hillforts, for example: Ness (MHG2151) and Skirza Head (MHG655) in Caithness; Dun Chealamy (MHG19718), Kilphedir (MHG9856), and An Dun (MHG9158) in Sutherland; Dun Cruinn on Skye (MHG6488); and Dun Lagaidh, Wester Ross (MHG7812). Other evidence suggests the siting of cARs near an even earlier prehistoric past. For example at Carn Liath, Golspie, the broch was built near a Bronze Age cist burial (MHG10872). There is also great scope re-analysing finds from old antiquarian excavations; a good example of what can be gleaned by looking at old finds from Caithness brochs is the publication by Heald and Jackson (2001).