What looks like an unremarkable spread of ground is, in fact, the remnant of a fulacht fia, a type of prehistoric cooking site found in great numbers across Ireland and particularly concentrated in Munster. The name translates loosely from Irish as "cooking place of the wild," and the sites typically consist of a horseshoe-shaped mound of burnt and shattered stone that accumulated over repeated use. The characteristic burnt material, fire-cracked rock discarded after heating, is exactly what survives here beneath the turf.

The mechanics of a fulacht fia are straightforward once explained. A trough, usually timber-lined or cut into the ground near a water source, would be filled with water. Stones were heated in a fire and dropped into the trough to bring the water to a boil, and food, most likely meat, was cooked in the resulting heat. The broken, heat-shocked stones were then thrown aside, building up the mound over time. Most examples in Ireland date to the Bronze Age, roughly 1500 to 500 BC, though some sites saw use across a much longer span. The proximity of the Caherdrinny example to a stream fits the pattern precisely; access to water was not incidental but central to how these sites functioned.