Yet the exposed earth told a different story: a dark seam of burnt material, the characteristic signature of a fulacht fia, cutting through the bank where the land met the water.

Fulachtaí fia are among the most common prehistoric monuments in Ireland, and among the most easily overlooked. They typically survive as low, horseshoe-shaped mounds of fire-cracked stone and charcoal-blackened soil, clustered near streams or marshy ground. The prevailing interpretation is that they functioned as outdoor cooking sites, where stones were heated in a fire and then dropped into a water-filled trough to bring it to a boil. The process leaves a very particular kind of residue: shattered, heat-fractured stone and scorched organic material, which can persist in the soil for three thousand years or more. That is precisely what appeared in the stream bank at Tullagh, exposed not by an archaeologist's trowel but by land drainage machinery. The discovery is a reminder of how much of the prehistoric landscape still lies just below the surface of ordinary agricultural land, waiting for a digger bucket to catch it at the right angle.