The mound measures roughly twelve metres east to west and five metres north to south, and it consists almost entirely of burnt material, the accumulated debris of repeated heating and cooling. What makes it more than a curiosity is that it does not stand alone: this is one of a cluster of five such monuments in close proximity, a concentration that hints at sustained activity rather than a single, incidental episode.

The monument is a fulacht fia, a type of site found in enormous numbers across Ireland, typically dating to the Bronze Age. The term refers broadly to an outdoor cooking place, the standard interpretation being that stones were heated in a fire, dropped into a water-filled trough to bring it to the boil, and used to cook meat. Over time, the shattered, heat-fractured stones were raked out and discarded, slowly building up the distinctive horseshoe-shaped or oval mound that survives today. The fact that five of these features exist within the same townland at Garranejames suggests the area was a focal point for such activity, perhaps over several generations, though whether the sites were used simultaneously or represent separate episodes across a longer span is difficult to say without excavation.