The monument comprises the remains of a fort, occupied probably in later prehistory between around 1200 BC and AD 400. The fort occupies the top of an isolated and conspicuous hill and is defined by traces of a low grass-grown rampart around the flat summit. The sides of the hill are extremely steep limiting access to the fort interior, except in the south-west where the slope is much more gradual. The site lies in a prominent position at approximately 300m above sea level, with extensive views over the surrounding landscape.
The fort occupies a hill which is oval-shaped on plan. The interior is defined by an ephemeral earth bank, which is more easily visible on aerial photographs. On the ground, traces of the ramparts are visible on the WSW, NW, E and S sides. On the N side the bank measures around 2m wide and 0.25m high. The fort interior, which is triangular on plan, measures around 87m WSW-ENE over the ramparts and varies in width from around 60m in the ENE to 18m at the entranceway in the WSW. The entrance measures around 2m wide between ramparts measuring around 5m wide and up to 1m high. An exposed section of the rampart reveals it is of rubble and earth construction. Traces of a second horse-shoe shaped rampart around the lower slopes, 20m downslope of the upper rampart, can be seen on aerial photographs. Within the W part of the interior of the fort, two hollow areas may represent the remains of hut circles. At the E end of the fort interior is a natural raised area forming a slight plateau 4m wide, which may have been modified.
The area to be scheduled is irregular on plan, to include the remains described and an area around them within which evidence relating to the monument's construction, use and abandonment may survive, as shown in red on the accompanying map. Specifically excluded from the scheduling to allow for maintenance are the upstanding elements of stone dykes and sheep folds found on the lower slopes.
Statement of National Importance
The monument's cultural significance can be expressed as follows:
This monument represents a later prehistoric defended settlement with good evidence for earth and stone ramparts around the summit and the bottom of slope. In addition, the remains of a medial rampart halfway down the slope have been noted in the past. The hilltop setting and ramparts, though probably never very large, show defensive concerns were among the factors influencing the choice of site. Although the visible upstanding remains are relatively low, there is potential for complex archaeological remains of banks and ditches to survive below ground. These remains can help us to understand more about the construction, use and abandonment of the defensive structures, helping to inform our understanding of the character of late prehistoric defended settlement in this area. Evidence may also exist for how the inhabitants of the settlement interacted with other societies within the region and incoming peoples such as the Romans.
The slight hollows and plateau noted within the interior have a high potential for preserving domestic structures and the fort's situation on marginal unimproved land suggests that levels of preservation will be excellent. Buried architectural features within the interior have the potential to provide evidence for the design, construction, phasing and use of buildings. Excavations at other Iron Age settlement sites have revealed the potential for the survival of fragmentary human remains within and around domestic structures, some of which show evidence of curation and structured deposition. The monument therefore has a potential to further our understanding of the treatment of human remains during this period, as well as increase our knowledge of pathology and details of population. Potential also exists for the survival of buried land surfaces beneath the rampart and other upstanding features. These could preserve information about the environment before and when the site was constructed, adding to the time-depth represented by the remains. Cut features such as post-holes and pits may contain archaeologically significant deposits that can further our understanding of society, ritual, economy, agriculture and, potentially, domestic architecture.
Defended settlements and forts were built at various times from the late Bronze Age (starting around 1200 BC) until probably the end of the early Middle Ages (around 1000 AD). Although excavation elsewhere indicates that the first defensive systems appeared in the Bronze Age, the majority of monuments excavated so far have produced evidence for Iron Age occupation, ranging from the mid to late 1st millennium BC.
Researchers have identified relatively few defended settlements in the former county of Renfrewshire compared to other areas of Scotland. The known sites range from small settlements, often known as 'homesteads' and measuring less than around 50m in diameter, to larger forts. Most are characterised by relatively small-scale defences, typically stone banks or walls built on or near to hilltops to enhance the natural relief. Homesteads such as Knockmade Hill and Knapps may have been occupied in the late Bronze Age and excavation at the latter produced evidence of a wooden palisade, erected early in the history of the site. Larger settlements also have the potential to originate at a relatively early date and the hillfort at Craigmarloch, around 29km north-west of Dunwan Hill, produced evidence for a palisade that predated a timber-laced rampart and may date to around 800 BC. Both small homesteads and larger hillforts appear to have continued in use through much of the late 1st millennium BC. Researchers have interpreted the hillforts as suggesting the emergence of small tribal units. The hillfort at Walls, for example, around 16.7km NW of Dunwan Hill and the largest hillfort in the former county of Renfrewshire, may have had such a function. There is no evidence that Dunwan hillfort has been excavated and there is much to learn about its precise function. Nevertheless, its high archaeological potential means that it has particular potential to contribute towards a better understanding of prehistoric forts and defended settlements in this area, particularly those in elevated positions. Their construction and layout including size, number of entrances, design and placement in the landscape are all important in understanding this type of monument. By comparing this monument to others of its type we can learn more about defended settlements and associated dwellings in the former county of Renfrewshire and more widely across Scotland.
The monument is of national importance because it has an inherent potential to make a significant addition to the understanding of the past, in particular the study of forts and defended settlements in later prehistoric SW Scotland. It survives in good condition above ground and it is probable that extensive and complex archaeological remains exist below ground relating to the construction and use of the ramparts and internal features. There is a high potential for the survival of buried material, including artefacts and ecofacts relating to the use or abandonment of the fort. The monument has the potential to tell us about wider prehistoric society, how people lived, where they came from and who they had contacts with. Its importance is increased by its proximity to other monuments of potentially contemporary date and its capacity to inform us about the nature of relationships between monuments of similar function. Spatial analysis of sites may inform our understanding of patterns of landholding and the expansion of settlement. Its loss or diminution would impede our ability to understand the placing of such monuments within the landscape both in the former county of Renfrewshire and in other parts of Scotland, as well as our knowledge of later prehistoric social structure and economy.