The mound is a fulacht fia, a type of ancient burnt mound found in enormous numbers across Ireland, typically beside a water source. The method involved heating stones in a fire until they were red-hot, then dropping them into a water-filled trough to bring it to a boil. Over repeated use, the shattered, heat-spent stones were raked out and discarded, building up the characteristic horseshoe-shaped mound that survives to this day.

The mound at Carragraigue sits to the north-west of a spring, which would have provided the water essential to the whole operation. What remains on the east side of a field drain and fence measures roughly 6.85 metres long, 7 metres wide, and 1.5 metres high, a substantial survival. The drain and the lowering of the field level on the western side have likely accounted for the rest, leaving only the eastern portion intact. It is a small, quiet casualty of agricultural improvement, the kind of damage that has reduced or erased countless such monuments across the Irish landscape, though what persists here is still coherent enough to read as a mound.