A souterrain is an underground stone-lined passage or chamber, typically built during the early medieval period as a place of refuge or storage and associated with ringforts, the circular enclosed farmsteads that once dotted the Irish countryside in their thousands. This particular example sits in the northern half of one such ringfort and has left no visible trace on the surface whatsoever.

What makes the situation at Kilpatrick quietly interesting is the paper trail left by its gradual disappearance from view. By 1940, the six-inch Ordnance Survey map was already marking the location as a 'site of' rather than a confirmed, visible feature, suggesting that within living memory of that survey, whatever surface evidence once existed had already been lost to agriculture, vegetation, or simple time. A second possible souterrain has been identified in the south-western quadrant of the same ringfort, which, if confirmed, would make this enclosure doubly significant. Two souterrains within a single ringfort is not unheard of, but it is far from typical, and the pairing raises questions about the scale or complexity of activity once conducted here that are unlikely to be answered without excavation.