It would take a careful eye to notice it at all, and most walkers almost certainly pass it without a second glance. Yet that modest heap of burnt material is the remains of a fulacht fia, a type of prehistoric cooking site found in extraordinary numbers across Ireland, and one of the quieter pieces of evidence that this landscape was once regularly used and occupied.

A fulacht fia, in its simplest form, is the debris left behind by an ancient method of cooking or heating water. Stones were placed in a fire until they were intensely hot, then dropped into a water-filled trough, usually timber-lined and sunk into the ground, until the water boiled. The cracked and fire-damaged stones were discarded to one side after each use, and over time these accumulated into the low, horseshoe-shaped mounds that survive across the Irish countryside today. The majority date to the Bronze Age, roughly 1500 to 500 BC, though some examples are earlier or later. At Ré Na Ndoirí, the site lies within land that has been reclaimed as pasture, a process that tends to flatten and obscure surface archaeology, which goes some way towards explaining why this particular mound is described as barely discernible.