In the pasture on an east-facing slope near Kilmacogue, the grass itself gives the game away, growing in a circular pattern that marks out something buried long beneath the surface. This is a ring-ditch, the circular trench or series of pits that once surrounded a burial mound or enclosed a ceremonial space in prehistoric Ireland. The mound itself may have long since been ploughed flat or eroded away, but the ditch cut into the subsoil persists, and under the right conditions, the overlying vegetation tells on it.

The feature came to attention through a cropmark visible on aerial imagery, specifically an orthoimage from Apple Maps. Cropmarks form when buried features affect the moisture or nutrient content of the soil above them; ditches, which retain more material, tend to produce lusher, darker growth, while the outlines of old walls or compacted surfaces do the opposite. The resulting patterns, often invisible at ground level, can be read clearly from altitude, and it was in this way that the ring-ditch at Kilmacogue was identified. It sits approximately 175 metres east of Kilmacogue Castle, a tower house that itself belongs to a later chapter of the landscape's long occupation. The proximity of a prehistoric monument to a medieval structure is not unusual in Tipperary, where centuries of settlement have layered themselves one on top of another across the same favoured ground.