The one at Ballyviniter in north Cork does none of that. It exists, as far as the archaeological record is concerned, almost entirely as a ghost in a field, visible only from the air under the right conditions, when a dry summer draws the buried outline of a fosse up through the grass in faint strips of stressed or thriving crop.

A fosse is a ditch, typically dug around a settlement or enclosure for drainage, demarcation, or defence. At Ballyviniter, the fosse belongs to a roughly circular enclosure approximately forty metres in diameter, and it was first captured in an aerial photograph taken in July 1989 as part of a systematic aerial survey programme. What made the image particularly interesting was the relationship between this circular feature and a separate rectangular enclosure nearby. The circular enclosure does not sit independently in the landscape; its fosse projects from the north-western corner of the rectangular one, suggesting the two features are connected, perhaps sequential phases of use on the same plot of ground. The cropmark itself appears in two slightly different forms depending on the direction: as a single band running from south to north-north-east, and as two narrower parallel bands in the opposite direction, a distinction that likely reflects the width or fill of the original ditch.

Beyond the aerial photograph there is little else on record for this site. No excavation appears to have taken place, so the date of the enclosure, its function, and the nature of any activity within it remain open questions. Circular enclosures of this scale in Ireland are frequently associated with early medieval ringforts, used as farmsteads or defended homesteads between roughly the fifth and twelfth centuries, but without further investigation the Ballyviniter example cannot be pinned to any particular period or purpose. It is, for now, a shape beneath a field.