The site recorded here is the most easterly of the three, a low, unassuming mound of burnt stone and ash roughly six metres across and less than half a metre high. To the untrained eye it would read as a slight rise in a boggy field, but that modest hump is the accumulated debris of a prehistoric cooking method repeated so many times that it left a permanent mark on the landscape.

A fulacht fia is a type of outdoor cooking site found in great numbers across Ireland, typically Bronze Age in origin, and usually identified by exactly this kind of horseshoe-shaped or oval mound composed of fire-cracked stone. The process involved heating stones in a fire and dropping them into a water-filled trough to bring the water to a boil, cooking meat or other food. The cracked, spent stones were then discarded to the side, building up the mound over time. This particular example sits on level ground that was formerly marshy, at the south-eastern end of a north-to-south ridge, with a stream nearby that has been deepened into a drain running about two metres to the south. Water access was essential to the whole enterprise, and the original boggy, waterlogged ground would have made this an ideal location. The proximity of two further fulachta fia, at roughly eight and sixteen metres to the south-west, suggests this corner of Glenmagoo saw repeated or sustained use, perhaps across generations, by people who returned to the same reliable water source and flat, wet ground.