No earthwork rises from the field, no stones break the surface. Yet from the air, on a summer afternoon in 1971, a ghost emerged. A cropmark, the kind of faint discolouration that appears in ripening grain or dry grass when buried features alter how the soil retains moisture, revealed the outline of a roughly square enclosure measuring approximately 45 metres across its northeast to southwest axis. A cropmark of this kind typically indicates a fosse, a defensive ditch, that was cut into the ground long ago and later filled in, leaving a buried anomaly that vegetation still responds to, centuries or millennia after the original structure disappeared.

The photograph that captured this, taken on 16 July 1971 as part of the Cambridge University Collection of Aerial Photography, shows something else of interest alongside the main enclosure. A second, slightly smaller square enclosure sits immediately to the northwest, and the two appear to be conjoined at their shared northwest angle, suggesting they may have formed part of a single complex or were at least laid out in deliberate relationship to one another. What makes the wider landscape around Dunbell Big particularly notable is the density of similar features nearby. At least five further enclosures have been recorded within roughly 330 metres in various directions, clustered to the north, west, southwest, and south-southeast. Whether these represent a settlement pattern from a single period, or an accumulation of features across many centuries of activity in this patch of Kilkenny farmland, the aerial evidence alone cannot say.