This kind of mark, known as a cropmark, forms when ancient ditches or disturbed ground retain moisture differently from the surrounding earth, causing the plants above them to grow taller or change colour in dry weather. The enclosure itself had long since vanished from the surface, but the ground remembered it.

The photograph, taken on 15 July 1968 as part of the Cambridge University Collection of Aerial Photography (reference CUCAP AVL084), recorded more than one such feature. The enclosure at Bramblestown, which shows both an outer and an inner fosse, a fosse being a defensive or boundary ditch, sits within a wider landscape of similar remains. Another roughly circular enclosure lies about 130 metres to the west, and part of a third is visible some 120 metres to the south-south-east. Also legible on the same photograph are the faint lines of field boundaries that still appeared on maps surveyed between 1899 and 1902 but had been physically levelled by the time the aircraft passed overhead. In a single image, then, several layers of history collapsed into one frame: prehistoric or early medieval enclosures buried beneath the soil, and more recent agricultural boundaries erased within living memory.

Circular enclosures of this kind are commonly associated with early medieval settlement in Ireland, the most familiar being the ringfort, though without excavation it is not possible to say precisely what this one was used for or when. What the clustering of three such features in close proximity does suggest is that this corner of Kilkenny was once a more actively organised landscape than its present fields imply.