This is a ring-ditch, and it exists, for most practical purposes, only from the air.

Cropmarks like this one form when buried features, such as the filled-in fosse, or enclosing ditch, of a former structure, cause the vegetation above them to grow differently from the surrounding soil. In dry conditions especially, the subtle variations in soil depth and moisture content produce faint but readable differences in crop colour and height. The ring-ditch at Ballyda measures approximately five metres in diameter, placing it at the smaller end of such features. What it originally enclosed is not recorded, though circular ditched enclosures of this kind are frequently associated with prehistoric funerary or ritual activity. A second, larger ring-ditch lies roughly a hundred metres to the north-north-east, which raises the possibility that the two are related, perhaps part of a spread of activity across this patch of Kilkenny farmland that has left no surface trace whatsoever.