Measuring roughly eight metres east to west and five metres north to south, the mound is barely prominent enough to catch the eye, identifiable mainly by the thick covering of grass, rushes, and gorse that crowns it, and by the dense concentration of stone fragments embedded in dark grey and black soil beneath. Its exact edges are uncertain, which is itself a common feature of these kinds of sites, where centuries of agricultural activity and weathering have softened any original definition.

This is a burnt mound, a type of prehistoric site found across Ireland and Britain in considerable numbers, and typically interpreted as the debris from a cooking or heating process involving fire-cracked stones. The usual method involved heating stones in a fire, then plunging them into a water-filled trough to bring it to the boil. The stones, fractured and blackened by repeated heating and cooling, were then discarded into a growing heap nearby, producing the characteristic dark, crumbly mounds that survive today. Closely related are fulachta fia, a term sometimes used interchangeably with burnt mounds, though the distinction broadly follows archaeological convention: a fulacht fia refers to the whole cooking site including any trough, while a burnt mound describes the spoil heap itself. What makes the field at Steelaun genuinely unusual is the density of such remains within a very small area. Within eighty-five metres of this mound lie four further sites of the same type, including two fulachta fia and another burnt mound only eight metres to the north-west. The natural terrace here, sitting in a shallow basin of moisture-retaining ground with a steep ridge rising to the north-west, would have offered reliable access to water and some shelter, conditions that seem to have attracted repeated activity, possibly across many generations of prehistoric use.