Beneath ground that gave no hint of anything unusual, soil stripping revealed a fulacht fia, one of the low, scorched mounds found in their thousands across the Irish landscape. A fulacht fia is essentially a prehistoric cooking or heating site, built around a water-filled trough into which fire-heated stones were dropped to bring the water to a boil. The stones crack and shatter with repeated use, eventually accumulating into the distinctive mound of burnt, fragmented rock that archaeologists recognise today.

The excavation, carried out under licence in 2004 and reported by Zajac, uncovered a low mound of burnt stone measuring roughly 7.8 metres north to south and 4.2 metres east to west, though only about twenty centimetres deep. Beneath it lay a small rectangular trough, approximately 1.7 metres long and less than a metre wide, with rounded corners each marked by a stakehole. The stakes would once have supported a timber lining, and fragments of that lining survived: two highly degraded planks, tentatively identified as alder, still lay along the base of the trough. Alder is a wood well suited to wet conditions, which may partly explain its apparent use here. A shallow, kidney-shaped pit was found two metres to the north-east of the trough, its function unclear. The mound itself extended beyond the boundary of the road works and was not fully excavated, so part of the site remains undisturbed in the ground. Perhaps most striking is that a second fulacht fia lay just twelve metres to the east-north-east and was also excavated, suggesting this low-lying ground on the edge of Ballina was a place of repeated, deliberate activity in prehistory rather than a solitary occurrence.