When aerial photographers surveyed the area in July 1989, they captured a pattern of rectilinear cropmarks spread across roughly twenty hectares, the ghostly geometry of a field system that no longer corresponds to anything on the modern land surface. The axis of this buried network cuts across the orientation of the fields that exist today, which is itself a telling detail: it suggests that the landscape was substantially reorganised at some point after the original system fell out of use, erasing the surface traces while leaving the subsurface boundaries intact enough to influence how crops grow directly above them.

Cropmarks form when buried features such as ditches, walls, or trackways affect the soil's moisture content and nutrient levels, causing the vegetation above them to grow at a slightly different rate or shade of colour than the surrounding ground. Seen from altitude in dry summer conditions, these variations resolve into legible shapes. At Carrigleagh, the shapes include not only the rectilinear field boundaries themselves but also two circular enclosures and a ring-ditch, all sitting within the field system and connected to it by its own boundaries. Ring-ditches are typically the eroded remains of prehistoric burial monuments, while circular enclosures can represent anything from early medieval farmsteads to much older settlement sites. The fact that these features are integrated into the field layout rather than simply overlapping it suggests they may have been contemporary with the system, or at least that the fields were deliberately arranged in relation to them. Along the eastern edge of the whole complex, two closely spaced parallel cropmarks running roughly north-north-west to south-south-east have been interpreted as a possible routeway, a track or road that once served the community farming these lands.