A fulacht fia is a type of prehistoric cooking site found in enormous numbers across Ireland, typically consisting of a horseshoe-shaped mound of fire-cracked stones heaped up beside a water source and a trough. The idea was straightforward: stones were heated in a fire, dropped into a water-filled trough to bring it to the boil, and used for cooking. The discarded, shattered stones accumulated over repeated use into the characteristic mound shape. The one at Aughvallydeag followed this pattern closely, a near-textbook example sitting on high ground with open views in every direction, measuring roughly twelve metres north to south and just over eleven metres east to west, with a shallow depression in the eastern face marking where the trough once sat.

What made the arrangement at Aughvallydeag particularly clear was the presence of a natural spring immediately to the east of that trough area, providing the reliable water source that these sites invariably required. The mound itself stood about half a metre high and the trough depression reached a depth of around thirty centimetres. At the time of an inspection in 2006, the structure was still readable in the landscape. Sometime after that visit, however, the mound was levelled, most likely through agricultural activity, and the fire-cracked stones that once formed its body are now spread across the surrounding surface rather than held in their original form. What remains is a scatter of fractured stone across wet grass, the geometry largely gone, though the spring and the general topography still hint at why someone chose this spot, probably in the Bronze Age, to do the ordinary, necessary work of preparing food.