In July 1989, aerial photography captured a pattern of rectilinear cropmarks spread across roughly nine hectares, their right-angle junctions suggesting a planned, organised system of enclosures rather than anything casual or piecemeal. Cropmarks form when buried features such as ditches, walls, or banks affect the moisture available to growing crops above them, causing subtle but visible differences in colour and height at certain times of year. What the camera recorded at Cregg is a relict field system, meaning one that was abandoned long ago and has since been buried under later land use, surviving only as a ghostly geometry in the soil.

Within that nine-hectare spread, the aerial photographs reveal a cluster of features that point to sustained human settlement over time. There is a ringfort, the circular enclosed farmstead that was the standard unit of rural life in early medieval Ireland, along with four ring-ditches and a circular enclosure. Ring-ditches are typically the eroded or infilled remains of circular earthworks, sometimes associated with prehistoric burial or ritual activity, though their function varies considerably from site to site. The presence of multiple such features alongside the field system suggests that this corner of north Cork was not merely farmed but inhabited and organised across what may have been several different periods, each generation of activity leaving its own faint impression in the ground.