To most passers-by it would register as little more than a slight irregularity in the ground, a patch of rubble perhaps left by some forgotten agricultural activity. In fact it is a fulacht fia, one of the most common prehistoric monument types in Ireland, and one of the least understood.

Fulachtaí fia, the plural form, are typically Bronze Age in origin, dating broadly from around 1500 BC onward, though some may be earlier or later. They are identified by their characteristic horseshoe-shaped or spread mounds of heat-shattered stone, the broken material being the physical residue of a repeated process in which stones were heated in a fire and then plunged into a water-filled trough to bring it rapidly to the boil. What exactly the boiling water was used for has been debated for decades. Cooking, textile processing, bathing, and even brewing have all been proposed. The Ballynalouhy example, a low spread rather than a pronounced mound, suggests it has been considerably disturbed by ploughing over the years, its profile flattened and its stones dispersed across a fifteen-by-fifteen-metre scatter. A telegraph pole stands to the north, a mundane modern marker beside something several thousand years older.