Aerial photography has captured the site as a distinct oval cropmark, where differential plant growth traces the line of what was once a fosse, the encircling ditch that defined a ringfort. Ringforts, known in Irish as raths, were the most common form of rural settlement in early medieval Ireland, typically consisting of a circular or oval area enclosed by one or more earthen banks and their associated ditches. Thousands survive across the country in various states of preservation; this one, overlooking Lough Drin roughly 215 metres to the north-west, does not.

What makes the Clonsheever site quietly interesting is the way the historical record tracks its gradual disappearance. The Ordnance Survey six-inch map of 1837 recorded it as a pentagonal-shaped earthwork, an unusual form for a rath, while a companion OS Fair Plan map from the same year annotated it simply as a fort and showed it as circular. By the time the revised twenty-five-inch Ordnance Survey was published in 1913, the monument had taken on a roughly oval shape in the cartographic record, measuring approximately 51 metres on a north-west to south-east axis and 54 metres across the north-east to south-west. These shifting depictions may reflect the surveyors' differing interpretations of a degrading earthwork as much as any genuine change in shape. By 1970 it had gone entirely at ground level, described at that point as having no surface remains visible. The ditch, it seems, was backfilled rather than simply eroded, and it is the ghost of that infilled fosse that aerial photography now reveals through the behaviour of the crops or pasture above it.