A fulacht fia, to use the Irish term, is a type of burnt mound found across Ireland and Britain, generally interpreted as an outdoor cooking place from the Bronze Age. The method involved heating stones in a fire, dropping them into a water-filled trough to bring the water to boiling point, and using that heat to cook meat. The characteristic horseshoe-shaped mound left behind consists of the discarded burnt and shattered stones, and these mounds survive in their thousands across the Irish countryside, often in low-lying, waterlogged ground near streams or springs.

The site at Milleencoola was identified through a geophysical survey carried out under licence 17R0155, which flagged anomalies in the ground consistent with buried archaeological material. A subsequent test excavation, conducted under licence 17E0444, confirmed the presence of fulacht fia material at the base of the field. The excavation did not expose the full extent of the monument, but what was revealed measures at least twelve metres east to west and eight metres north to south, suggesting a site of some significance. The small stream running just to the south of it fits the pattern well; proximity to a reliable water source was, practically speaking, essential to how these sites functioned.