It is, in fact, the accumulated debris of prehistoric cooking, a fulacht fia, and it has been accumulating there since long before anyone thought to record it. A shallow depression marks its south-western end, and an old Ordnance Survey six-inch map places a pond roughly fifteen metres to the south-east, which is exactly where you would expect one to be.

A fulacht fia, sometimes called a burnt mound, is among the most common archaeological monuments in Ireland, yet they remain poorly understood in terms of the social lives they represent. The basic mechanics are reasonably clear: stones were heated in a fire and then dropped into a water-filled trough, bringing the water to a boil and sustaining that heat for cooking. The cracked and shattered stones, useless after a single heating, were discarded in a horseshoe or crescent around the trough, building up over repeated use into precisely the kind of low, heat-blackened mound visible at Kilcolman. Most fulachta fia date to the Bronze Age, broadly between 1800 and 800 BC, though some earlier and later examples are known. The mound here measures 14.6 metres along its north-west to south-east axis, a modest but typical size. The nearby pond recorded on the historical mapping corresponds well with the water source that any such site would have required, whether that was a natural pool, a boggy hollow, or a feature partly shaped by the activity itself over many generations of use.