It is, in fact, a fulacht fia, a type of prehistoric cooking site found in great numbers across Ireland, typically consisting of a horseshoe or kidney-shaped mound of fire-cracked stones accumulated beside a water source. The stones would have been heated in a fire and dropped into a water-filled trough to bring it to the boil, and over time the shattered, heat-spent fragments built up into the mounds we see today. At Carrowgarve, that process left a kidney-shaped deposit measuring roughly fourteen metres north to south and eight metres east to west, rising to just under a metre at its highest points to the north and west.

What makes this particular site quietly interesting is the indentation visible on its south-western side, facing the stream, which most likely marks where the cooking trough once sat. The relationship between mound and water is typical; fulachtaí fia are almost always found close to streams or marshy ground, and the Fiddaunglass, a tributary of the River Deel, would have supplied everything the process required. More striking still is that this mound does not stand alone. It belongs to a linear cluster of six such sites running along the course of the same stream, with another fulacht fia recorded just twenty metres to the north. Whether this grouping reflects repeated use of a favoured spot over many generations, or activity by a community making intensive use of a particular stretch of water, is not certain, but the concentration along a single watercourse gives the landscape an unusual density of prehistoric activity for what is now unremarkable grazing land. A few gorse bushes have colonised the mound itself, which is otherwise defined mainly by its moss covering and the slight hollow where the trough depression remains legible.