The two stones stand just 0.22 metres apart, their long axes running north to south, and both tilt as though slowly giving in to the slope. Were they fully erect, they would reach somewhere between 0.6 and 0.8 metres in height, which rules out the more commanding prehistoric monument types. A scatter of large slabs lies to their west, though some of these appear to have been deposited there rather than placed with any original intention, which only deepens the ambiguity.

The classification "anomalous stone group" is itself a telling phrase, used in Irish archaeological records when a setting of stones resists easy assignment to known monument types such as stone circles, alignment pairs, or portal tombs. What makes the location at Knocknagappul more interesting than the modest dimensions suggest is the density of prehistoric activity in the immediate vicinity. Within 250 metres to the southwest lies a wedge tomb, a Neolithic or early Bronze Age burial monument typically consisting of a roofed stone gallery that narrows toward one end. Two further anomalous stone groups are recorded nearby, one roughly 100 metres to the east-southeast and another around 150 metres to the southwest. The area sits on outcropping rock in upland pasture, the kind of terrain that was more heavily settled and used in prehistory than its current emptiness might imply.