It exists, at least to the modern eye, only as a cropmark, a phenomenon where buried ditches and banks cause the vegetation above them to grow differently, revealing ancient shapes from the air that vanish entirely at ground level. What the aerial camera caught in July 1989 was the fosse, or enclosure ditch, of a site approximately forty metres in diameter, its form emerging quietly from the soil only when photographed from above.

The photograph in question was taken as part of a systematic aerial survey and shows the fosse curving around on the eastern side of a field fence, with a slight outward bulge to the west that may indicate the position of an original entrance. Enclosures of this kind are among the most common monument types in the Irish countryside, typically associated with early medieval settlement, though without excavation it is impossible to say with confidence when this particular example was built or how it was used. What makes Poulnareagha worth noting is less any individual drama than the ordinariness of its situation: it sits within a broader field system, absorbed into the working agricultural landscape of north Cork for perhaps a thousand years or more, its ditch silted up and levelled, its interior long since ploughed or grazed, its existence confirmed only by the chance angle of sunlight on a summer's day in 1989.