It measures fourteen metres east to west and eleven metres north to south, rising to just under a metre in height, with a four-metre-wide opening facing north. What fills it is not soil or rubble in the ordinary sense, but burnt material, the accumulated debris of repeated prehistoric cooking. This is a fulacht fia, a type of site found in enormous numbers across Ireland, typically interpreted as an ancient outdoor cooking place where stones were heated in fire and then dropped into a water-filled trough to bring it to the boil. The distinctive horseshoe shape is formed by the discarded, heat-shattered stones thrown aside after each use.

The siting follows a pattern seen at fulachta fiadh throughout the country. Proximity to a water source was essential, and the stream a short distance to the north would have supplied the trough. These sites are generally dated to the Bronze Age, roughly 1500 to 500 BC, though some examples fall outside that range. What is particularly notable at Urraghilmore is that this mound does not stand alone. It belongs to a cluster of three such sites in the same area, suggesting repeated or sustained activity at this location across what may have been a considerable span of time. Whether that reflects seasonal gatherings, a particular convenience of the terrain, or something else entirely, the archaeology does not say.