On a south-facing slope in County Waterford, a low grass-covered bank traces an almost perfect circle across a hilltop knoll. It is quiet enough that by 1927, the Ordnance Survey was mapping it simply as a circular field, its original purpose apparently forgotten by the farmers working around it. Only the shape itself, persistent across centuries of agricultural use, hints at something older beneath the turf.

This is a rath, the Irish term for a ringfort, a type of enclosed farmstead typically built during the early medieval period, roughly between the fifth and twelfth centuries. Thousands of them survive across Ireland, ranging from modest earthen banks to more elaborate constructions with stone facing and deep external ditches. The Bleantasour example measures approximately 47 metres east to west and 43 metres north to south, defined by a stone-faced earthen bank between two and a half and five metres wide. The bank still stands to an internal height of between 0.75 and 1.3 metres, and slightly more on its outer face. A section of it has been removed along the north-west to north-east arc, which likely accounts for why no formal entrance is now visible; the original gap, a standard feature of ringforts, may have been lost in the same disturbance. There is no surviving fosse, the external ditch that often accompanied such banks. The site sits on a knoll overlooking the Colligan river, which runs on a north-east to south-west alignment roughly 300 metres to the south-east, a position that would have offered both drainage and a view of the valley below. The 1840 edition of the six-inch Ordnance Survey map already records it as a circular enclosure, suggesting its outline was legible even then, if not fully understood.