The feature in Garryncoonagh South measures roughly 38 metres in diameter and is defined by a fosse, essentially a wide ditch cut into the ground that once served as a boundary or enclosure, the signature of a ring-fort type monument that was once a common feature of the Irish rural landscape. That it escaped cartographic notice for so long says something about how many such sites remain folded into ordinary farmland, their outlines softened by centuries of ploughing, grazing, and weather.

The monument came to official attention not through ground survey but through the examination of oblique aerial photographs taken on 4 March 2006 by the Archaeological Survey of Ireland. Aerial survey has transformed Irish archaeology over the past few decades, allowing analysts to spot cropmarks, soil discolouration, and subtle changes in ground level that are entirely invisible at eye height. In this case, the circular form was subsequently confirmed on Digital Globe orthoimages captured between 2011 and 2013, as well as on Google Earth imagery, each source reinforcing the presence of the fosse that traces the monument's perimeter. The record was compiled by Fiona Rooney and uploaded to the Archaeological Survey database in November 2021, meaning this site has only formally existed in the public record for a handful of years.

The earthwork lies in pasture approximately 55 metres west of the townland boundary between Garryncoonagh South and Garryncoonagh North, which at least gives a rough spatial anchor for anyone interested in locating it. Access would depend on landowner permission, as is standard with monuments of this kind in agricultural settings. Because the feature is defined primarily by its fosse rather than any upstanding bank or wall, it is unlikely to be immediately legible on the ground; the geometry that makes it coherent only becomes apparent at a remove, whether from satellite imagery or from a slight elevation nearby. Visiting in late spring or summer, when differential grass growth above buried features sometimes sharpens the outline, offers the best chance of seeing anything at all.