That is, in a sense, the whole point. Somewhere beneath a cultivated field on a north-facing slope in County Cork, the outline of an ancient enclosure has been ploughed flat, leaving no trace on the surface whatsoever. The field carries on as fields do, and the enclosure carries on as a coordinate in an inventory, a ghost geometry of roughly thirty metres east to west and eighteen metres north to south.

What we know of it comes from the Ordnance Survey's six-inch map of 1842, one of the most forensically detailed cartographic exercises ever carried out in Ireland, produced during a period when many earthworks still retained enough form to be worth recording. At Scarriff, the surveyors noted a rectangular enclosure sitting against an east-west field fence along its northern edge. Enclosures of this general type are scattered across the Irish landscape in their thousands; they served many purposes over many centuries, from the ringforts and enclosed farmsteads of the early medieval period through to later agricultural and ecclesiastical uses, and without further investigation it is rarely possible to say with confidence what any one of them was for. What is certain here is that by the time anyone thought to look more closely, the enclosure had already been levelled, absorbed into the agricultural routine of the land around it. The 1842 map preserves its shape the way a photograph preserves a face, long after the original has gone.