Others exist only as faint signatures in a crop, invisible to anyone walking the land but legible from above to a camera mounted in a low-flying aircraft on a July afternoon in 1989. That is the case at Cornahinch in North Cork, where an aerial survey captured the ghostly outline of a circular enclosure roughly ten metres in diameter. What the camera recorded was a cropmark, a phenomenon where buried ditches or banks affect the growth of crops above them, producing subtle differences in colour or height that only become apparent from height and in the right light. The feature in question is the fosse, or ditch, that once defined the perimeter of this small enclosure.

At ten metres across, this is a compact structure, closer in scale to a large room than to a farmstead. It sits within a broader field system, suggesting it was part of an organised agricultural or settlement landscape rather than an isolated feature. Approximately 130 metres to the north-east lies a second circular enclosure, hinting that the two may have functioned in relation to one another, though the precise nature of that relationship remains unresolved. Circular enclosures of this kind are among the most common monument types in the Irish countryside, ranging from the substantial ring forts, known as raths, that served as enclosed farmsteads in the early medieval period, to smaller features whose purposes are less well understood. Without excavation, it is difficult to assign a date or function to the Cornahinch example with any confidence.