The monument is a broch, a complex and substantial stone-built roundhouse dating to the Iron Age (between 600 BC and AD 400). The monument is visible as a roughly circular drystone-walled structure with the remains of an outer wall. It is constructed on a rocky outcrop on the south side of Glen Colbost at approximately 30m above sea level.
The broch is positioned on the summit of a natural rock outcrop. The outer wall of the broch has an external diameter of 16.5m and measures up to 1.5m in high and almost 4m wide at the base. It has an entrance passage up to 1m wide in its northeast quadrant. A substantial upright slab on the north wall of the entrance passage is likely to be a door check. Opposite the door check, there is evidence for a guard cell. The east and south sides of the broch have evidence for a passage within the thickness of the wall. There is an indication of a rectangular structure in the broch interior probably relating to a secondary phase of development. A casing wall, strongly sloped, rests against the outer face of the broch on its west side. Approximately 10.5m east of the broch entrance are the slight remains of an outer wall running north-south across the rocky outcrop. To the northwest of the broch, the rocky outcrop has a break in the rock providing a sloped approach to the broch from the level ground below.
The scheduled area is irregular on plan to include the remains described above and an area around them within which evidence relating to the monument's construction, use and abandonment is expected to survive, as shown in red on the accompanying map.
Statement of National Importance
The cultural significance of the monument has been assessed as follows:
The monument is an example of a broch, visible as drystone-walled structure set on the top of a rocky outcrop. Overall the site survives in very good condition with good structural and field characteristics, and no record of an excavation. The level of preservation of the broch together with the remains of outer-works are an important part of the monument's intrinsic characteristics.
The monument has very high potential to support future archaeological research. It has significant structural features such as walling, a door check, guard cell and wall passage and it is probable that additional buried features also exist. By analogy with other excavated brochs there is potential for buried remains of further wall cells and stairs, scarcement ledges, internal stone partitions, hearths and water tanks within the broch. There is also potential for the buried remains of outbuildings beyond the broch. Many of these features can provide information about broch architecture and construction methods. Additionally, the broch outworks and any associated structures are likely to contain deposits rich in occupation debris, artefacts and palaeoenvironmental evidence that can tell us about how people lived, their trade and exchange contacts, and their social status.
Brochs are typically thought to date from the mid first millennium BC through to the early part of the first millennium AD. There are few precise scientific dates for brochs on Skye and their dating has traditionally been based on typological studies of artefacts recovered from broch sites. The presence of features such as the casement wall and outer wall at this broch indicates this site may have had a complex development sequence. The rectangular feature within the broch indicates that there was a period of secondary reuse of the broch which adds to its significance.
Broch towers are primarily seen as a specific, specialised development of complex Atlantic roundhouses. They were large complex structures that could have accommodated either an extended family or a small community. While there would have been a social hierarchy within this community, the construction of these elaborate towers is often understood in terms of elite settlement. Other interpretations have stressed their likely role as fortified or defensive sites, possibly serving a community across a wider area. Brochs are complex structures likely to have had numerous purposes and a complex role in prehistoric society.
Brochs are a widespread and well recognised class of monument across northern Scotland and with notable concentrations in Caithness, Sutherland, Orkney, Shetland, the Western Isles and the northwest Highlands. This example is one of a local group on the Isle of Skye, but in two respects it is unusual in its local context. Firstly, Dun Arkaig is approximately 4km from the sea, whereas most brochs on Skye lie much closer to, or on, the coast. Secondly, the external casement wall is a feature not identified at any other west coast broch but resembles features found against some Orkney and Caithness brochs.
This monument is also significant as an upstanding and well-preserved example of a broch with associated outworks, which is located in proximity to a several other brochs including Dun Beag 4km south-southwest (scheduled monument reference SM90325 and Canmore ID 11062); Abhainn Bhaile Mheadhonaich 4km west (Canmore ID 1114) and Dun Garsin 4km south-southeast (scheduled monument reference SM912 and Canmore ID 11047). There is therefore potential for comparative study on a local and national scale to better understand the function of such monuments, their interrelationship and the significance of their placing within the landscape, in particular in relation to our understanding of Iron Age social hierarchy, changing settlement patterns and systems of inheritance.
The broch sits on the northwest facing slope of Glen Clobost in a prominent position on a rocky outcrop which is naturally strong. From the broch, there are wide open views along the valley down to the coast. Many broch towers were deliberately sited to be focal points in the landscape. This example is clearly visible from within the valley, which may have been the territory directly associated with or controlled from the broch.
There are no known associative characteristics which significantly contribute to the site's cultural significance.
Statement of National Importance
The monument is of national importance because it makes a significant addition to our understanding of the past, in particular the function, use and development of brochs on Skye. It is a well-preserved example of a broch that retains significant architectural features. The casing wall in particularly is very unusual in the context of west coast brochs. There is high potential for additional buried remains, including occupation debris, artefacts and ecofacts. This broch is a prominent feature in the landscape and adds to our understanding of the siting of brochs. This in turn can help our understanding of settlement patterns and social structure during the Iron Age on Skye. This potential and interest is enhanced by the proximity of other brochs and the unusual inland location of this monument for a Skye broch. The loss of the monument would diminish our future ability to appreciate and understand the use of brochs on Skye, and the nature of its Iron Age society, economy and social hierarchy.