A fulacht fia, known in older literature as a fulacht fiadh, is a type of outdoor cooking place found in enormous numbers across Ireland, typically identified by a horseshoe-shaped mound of fire-cracked stone and charcoal beside a water source. The principle was straightforward: stones were heated in a fire, then dropped into a water-filled trough to bring it to the boil. What makes the Ballynabarny sites quietly compelling is the detail that survives in each, and the long argument between human activity and a persistent spring that played out across the same ground for thousands of years.

The rescue excavation ran from 5 December 2001 to 20 February 2002. In the area locally known as the Long Field, the first and larger fulacht fia sat beside a natural spring whose water appears to have flowed downhill to the north-east throughout the Bronze Age. A subrectangular trough, measuring 2.3 metres by 2 metres and nearly half a metre deep, lay 4 metres south-east of the spring and would have filled naturally with water. Around it, excavators found pits, post-holes, and stake-holes filled with charcoal-rich soil and burnt stone; a central oval pit, 1.4 metres by 0.96 metres, showed evidence of in situ burning at its base and may have been used to heat the stones. The post- and stake-holes suggest some kind of temporary structure or windbreak, and the fact that it appears to have been deliberately dismantled points to seasonal or short-term use. About 30 metres to the north-west, a second, smaller fulacht fia clustered around what had once been a small natural pond, with three troughs ranged around it, the largest measuring 4.2 metres by 2 metres. A kilometre to the south, in a field the locals call the Well Field, four pits and two field boundary ditches were uncovered; one pit contained 83 pieces of struck flint and 28 sherds of probable Bronze Age pottery.

The later history of the Long Field is itself an odd kind of palimpsest. Every farming generation after the Bronze Age treated the spring not as a resource but as a nuisance to be redirected. A pair of parallel ditches, visible on the 1839 Ordnance Survey map but gone by the 1904 edition, had been dug to drain the spring water toward a low-lying area known as The Hollow on the far side of the N11. When those ditches were backfilled and the field boundary removed, the spring reasserted itself, and a new system of stone drains was laid directly over its source. The Bronze Age burnt spread, roughly horseshoe-shaped and covering about 15 square metres, had been further disturbed by centuries of ploughing before the excavators reached it. The road scheme that triggered the dig has long since been completed; the sites themselves now lie beneath the carriageway.