Somewhere on a south-east-facing slope in Killerguile, County Waterford, sits a circular earthwork that nobody appears to have entered, at least not by any obvious route. The enclosure, roughly 27 metres across, rises about a metre above the surrounding ground as an overgrown platform, defined on its north-western side by a flat-bottomed fosse, the kind of ditch cut to demarcate or defend a space, and by a scarp on the remaining sides. No entrance is visible anywhere around its perimeter, which gives the whole thing a quietly puzzling quality. Either the original threshold has been lost beneath centuries of vegetation and soil movement, or access was always managed in some way that left no lasting trace.

What makes the site stranger still is the object sitting on the outer edge of the fosse at the north. A bullaun stone, roughly 1.2 metres long and up to 0.9 metres wide, rests there with a single carved basin worn into its surface, about 0.4 metres across and 0.2 metres deep. Bullaun stones are boulders or rock slabs, usually of some antiquity, into which one or more cup-shaped hollows have been deliberately ground. They appear widely across Ireland, often near early ecclesiastical sites or ancient boundaries, and are sometimes associated with curative or ritual use, though their precise origins and purposes remain debated. Here, the bullaun sits not inside the enclosure but at its edge, on the lip of the ditch, as though positioned at a threshold rather than at a centre. Whether that placement reflects an original intention or is simply the consequence of later disturbance is impossible to say. A stream runs roughly 80 metres to the south, down in the valley below, and the whole arrangement, enclosure, fosse, and bullaun, occupies the quieter northern slope above it.