It measures roughly six and a half metres east to west and eight metres north to south, and to an untrained eye it might pass for nothing more than a slight irregularity in the field. What it actually represents is one of the most common yet persistently mysterious monument types in the Irish archaeological record.

This is a fulacht fia, a term used to describe the horseshoe-shaped or oval mounds of fire-cracked stone and charcoal that survive in their thousands across Ireland, particularly in low-lying or waterlogged ground. The standard interpretation is that these sites were used for cooking, most likely by heating stones in a fire and dropping them into a water-filled trough until the water boiled. The burnt and shattered stones were then discarded to the side, gradually building up the mound over repeated use. They date broadly to the Bronze Age, though some examples have produced dates stretching into the early medieval period. The precise social context of their use, whether for communal feasting, hide-working, bathing, or some combination of purposes, remains a matter of ongoing debate among archaeologists. The example at Gurteenroe is modest in scale but entirely typical in character, its scorched material preserved beneath the turf of what was once wetter ground before agricultural improvement changed the local drainage.