This one in Carrowkilleen, County Galway, offers nothing of the sort. What survives is essentially a cartographic ghost: a circular enclosure roughly 27 metres across, dutifully recorded by the Ordnance Survey in 1838, sitting in an area of scrubland and outcropping rock, and now leaving no visible trace whatsoever on the ground.

The site is classified as a cashel, a type of ringfort defined by stone rather than earthen walls. Ringforts in general were enclosed farmsteads of the early medieval period, typically dating from around the sixth to the twelfth century, and they are among the most common archaeological monument types in Ireland. The cashel variant was particularly suited to the rocky landscapes of the west, where building material lay ready to hand. At Carrowkilleen, whatever walls once defined this enclosure have long since vanished, robbed out for field boundaries or simply collapsed into the thin soil. Intriguingly, the 1922 edition of the Ordnance Survey map shows a slightly curving field boundary at the site's south-western edge, and it is possible that this curve is no accident, that a farmer drawing a boundary line followed, consciously or not, the arc of a wall that had been disappearing for centuries before him.

There is nothing here for a visitor to see in any conventional sense, and that is rather the point. The site belongs to a category of place that exists more fully in maps and records than in the landscape itself, its presence detectable only by reading one historical document against another and noticing where the lines curve in ways that topography alone cannot explain.