There is nothing to see from the ground, no earthwork, no rise in the soil, no visible boundary. The only reason anyone knows it exists at all is a single aerial photograph taken in 1970, on which the arc of the enclosure showed up as a cropmark, the faint but legible signature that buried features leave on growing crops when differential moisture or soil disturbance causes plants above them to ripen at a slightly different rate or colour from their neighbours.

The photograph in question, catalogued as CUCAP BDL 33, was taken in 1970 as part of the Cambridge University Collection of Aerial Photography, a programme that documented enormous numbers of archaeological sites across Britain and Ireland from the air, capturing features that centuries of ploughing had rendered invisible at ground level. What it recorded at Rathlogan was the arc of an enclosure sitting on the valley floor, positioned just above the flood plain, with open views across the surrounding landscape in every direction. A field boundary running northeast to southwest now cuts directly across the monument, dividing whatever remains of the original feature beneath the soil. Whether the enclosure was a settlement, a ritual site, or something else entirely is not known. Its diameter places it well within the range of enclosed farmsteads common in early medieval Ireland, though without excavation the date and function remain open questions.