It measures 1.8 metres across and tapers through a wedge-shaped cross-section from nearly half a metre thick at its southern end to a quarter of a metre at the north, where its top edge rounds off into something almost delicate. The long axis runs north to south, the two broad flat faces turned east and west, towards the Ox Mountains on one side and the open ground falling away towards Nephin Mountain on the other.

Standing stones are among the most enigmatic survivals of prehistoric Ireland, raised anywhere from the Neolithic through to the early medieval period, and their original purposes remain largely a matter of speculation, ranging from territorial markers to ceremonial focal points to astronomical alignments. What makes Carrowcrom more than a solitary curiosity is its immediate neighbourhood. A possible second standing stone sits roughly 90 metres to the west, and 120 metres to the southwest there is a stone row, a linear arrangement of upright stones whose function is equally debated but which suggests this corner of the townland once held some organised, deliberate significance. The stone has been marked on Ordnance Survey maps since at least 1838 and again on the 1922 six-inch edition, which at least confirms it was already conspicuous to early surveyors. It is a National Monument in state ownership. A small river runs just 25 metres to the north, and the townland boundary of Carrowcrom follows that watercourse, meaning the stone stands almost precisely at the edge of its named place.