A small multivallate hillfort known as 'Castle-an-Dinas' which contains an 18th century folly called 'Roger's Tower'

Scheduled area

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History & significance

A small multivallate hillfort known as 'Castle-an-Dinas' which contains an 18th century folly called 'Roger's Tower' is a well-preserved Iron Age defensive enclosure occupying a prominent granite-capped summit in the parish of St Columb Major in mid-Cornwall. The site commands an elevated position above the surrounding agricultural landscape of the Cornish interior, affording extensive views in all directions across the peninsula and offering a clear demonstration of why its Iron Age builders selected this particular eminence. At roughly 700 feet above sea level, the hill stands as one of the more conspicuous landmarks in this part of Cornwall, its silhouette marked by the distinctive tower that was added to it in the eighteenth century. The name 'Castle-an-Dinas' is itself a reflection of the Cornish language, meaning broadly 'the fort on the fortified hill', a designation that speaks to a continuous folk memory of the site's ancient defensive function long after its original inhabitants had passed from historical record.

The hillfort was constructed during the Iron Age, most probably in the first millennium BC, by the indigenous tribal communities who inhabited Cornwall during that period. These communities, predecessors of the Dumnonii whose territory encompassed much of south-western Britain, were capable of organising substantial communal labour to create defensive works of considerable scale. The precise circumstances that prompted the construction of Castle-an-Dinas are not recoverable from documentary sources, since the pre-Roman peoples of Cornwall left no written records of their own. However, the elaboration of its defences into multiple concentric ramparts is broadly consistent with the regional tradition of multivallate hillfort construction seen across Cornwall and the wider south-west, often interpreted as a response to both inter-tribal competition and the social prestige associated with controlling prominent high ground. The site is one of several hillforts in Cornwall bearing the 'Castle-an-Dinas' name, which reflects how deeply this class of monument became embedded in local Cornish consciousness and nomenclature.

The physical remains at Castle-an-Dinas are substantial and impressive, comprising three roughly concentric ramparts with accompanying ditches that encircle the summit of the hill. The innermost enclosure is the smallest, defined by a bank and ditch that surround the very crown of the hill, and successive outer ramparts step down the hillside to create the characteristic multivallate profile from which the monument derives its modern classification. The ramparts are constructed from the material thrown up when the ditches were cut, and they retain considerable height and coherence despite millennia of exposure and weathering. The overall enclosed area is relatively modest in comparison with some of the larger hillforts of southern Britain, consistent with the general character of Cornish Iron Age enclosures, which tend towards smaller, more intensively fortified sites rather than the vast territorial oppida found further east. The granite bedrock of the hill contributes to the robustness of the earthworks, resisting the erosion that has more severely damaged comparable sites on softer geology.

Standing within the innermost enclosure is Roger's Tower, a small rubble-built circular folly erected during the eighteenth century and named after a member of the local Glanville family who were prominent landowners in the St Columb Major area at that time. The tower is characteristic of the landscape improvement tradition fashionable among the English and Cornish gentry of the period, when the embellishment of prominent viewpoints with picturesque structures was considered a mark of cultivated taste. It is a modest structure but a conspicuous one, and while it has no defensive or functional significance, it adds an additional layer of historical interest to the site by illustrating the ways in which prehistoric monuments were consciously appropriated and romanticised by later generations. The juxtaposition of this eighteenth-century conceit with earthworks more than two thousand years older gives the site an unusually layered character.

Castle-an-Dinas is scheduled as an ancient monument because of the exceptional quality of its surviving earthworks and the importance of the archaeological deposits that almost certainly survive beneath the ground surface within and around the ram

A small multivallate hillfort known as 'Castle-an-Dinas' which contains an 18th century folly called 'Roger's Tower' is a scheduled monument protected by Historic England under reference 1006725. View the official record →

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