Exploring coastal promontory forts

The group has visited several promontory forts, so I thought a bit of background information might be useful.

 

Promontory forts are a feature of the landscape on many of the west-facing coastlines of the British Isles and they can also be found in Iberia and NW France. The indented coastline is a necessary common factor, but it may be that these widespread communities had something else in common that required them to build these forts. The vast majority of excavated sites have provided evidence of activity during the Iron Age, but precise dates are rare (an exception being Gob Eirer, Lewis which was radiocarbon dated to 600-500 BC).

Promontory forts are the largest group of forts in Atlantic Scotland, but they are not a homogeneous settlement type, distinct from the rest of the regional settlement pattern, but instead share characteristics with inland settlements.

The most common form is the univallate type, featuring a simple stone wall and usually enclosing less than one hectare. In some cases (e.g. Rubh an Dunain), features such as intra-mural galleries, borrowed from complex Atlantic roundhouses, have been incorporated into the wall. At the Broch of Burland in Shetland, a complex Atlantic roundhouse has been built on a small promontory and protected by multiple banks and ditches.

At least 50 promontory forts have been recorded along the Galloway coast, but only a handful have been excavated. Excavations at Carghidown demonstrated sporadic occupation over a short period during the late first millennium BC or early first millennium AD. Lead beads were discovered during the excavation, suggesting that the inhabitants were of some status within the local social hierarchy. The excavation also demonstrated that the site was only formally enclosed during the latter stages of its occupation and that within a year or two of this act of enclosure the ramparts were violently thrown down, the repair and construction of buildings within the settlement was abruptly halted and occupation ceased.

Although one or two hut platforms have occasionally been found within promontory forts, it seems unlikely that they were permanent domestic residences. Some of the larger enclosures could have performed a similar function to that of inland forts, offering temporary shelter to people and livestock, but many were little more than jagged outcrops of bare rock.

One interesting theory is that the more accessible sites were trading posts, with the function of the wall being to protect high value merchandise. For this theory to be valid, there would have to be a convenient mooring point nearby. Alternatively, a promontory fort may have been built to enable the local population to get advanced warning of the visit of a trading vessel to the local port.

In his study of promontory forts in northern Scotland, Lamb has noted that the majority of sites could not be simply explained as defensive or domestic locations and therefore considered them to have a social significance beyond the humdrum activities of everyday life. It is known that liminal places, such as the interface between land and sea, were particularly favoured as sites for communing with the supernatural, so some authors have suggested that promontory forts may have functioned primarily as places of ritual observance and worship.

Bibliography

Cunliffe, B.W. Facing the Ocean: The Atlantic and its Peoples, 8000 BC to AD 1500 (2001)

Harding, D.W. The Iron Age in Northern Britain (2004)

Henderson, Jon C. The Atlantic Iron Age (2007)

Lamb, R.G. Iron-Age Promontory Forts in the Northern Isles (1980)

Toolis, Ronan Intermittent occupation and forced abandonment: excavation of an Iron Age promontory fort at Carghidown, Dumfries and Galloway, Proc Soc Antiq Scot. 137 (2007) 265-318