Cropmarks appear when buried features, such as ditches or pits, affect the moisture and nutrients available to plants overhead, causing them to grow taller or more vigorously than the surrounding crop, and so tracing the outline of structures that might otherwise go entirely unnoticed. The photograph, part of the Cambridge University Collection of Aerial Photography, preserved the ghost of a feature that the landscape itself had long since closed over.

A ring-ditch of this kind is generally understood to be the remains of a circular ditch, often the eroded remnant of a prehistoric burial monument, its central mound long since ploughed flat. What makes the Foulksrath example particularly interesting is that it does not stand alone. A second ring-ditch of similar dimensions lies approximately 120 metres to the west-southwest, suggesting that whatever funerary or ritual activity once took place here left more than one trace in the soil. Such paired or clustered monuments are not unusual in the Irish landscape, where Bronze Age communities often returned to the same areas over generations, though the precise date and nature of these two features at Foulksrath has not been established from surface evidence alone.