It exists, for all practical purposes, only from the air, visible as a cropmark, the faint differential in how grass or grain grows over buried archaeology, betraying the outline of something that has long since lost any surface expression.

The enclosure was identified through aerial photography by Dr. D.D.C. Pochin Mould, and what the photographs revealed was a univallate circular enclosure, meaning one defined by a single bank or ditch, roughly 40 metres in diameter. A univallate enclosure of this kind is a common enough form in the Irish landscape, most often associated with early medieval settlement, the type sometimes called a ringfort, where a farmstead or small community enclosed itself within an earthen boundary. What gives the Rosslague example a particular quiet interest is its proximity to a second circular enclosure, recorded separately, lying approximately 80 metres to its west. Paired or closely grouped enclosures are not unknown in Ireland, and their relationship, whether contemporary, sequential, or coincidental, is the kind of question that aerial evidence alone cannot answer.