A cairn, in the broadest sense, is a mound of stones raised over a burial or as a landscape marker, often dating to the Bronze Age or earlier; this one has lost much of its definition, but its dimensions, roughly 8.2 metres east to west and 7.9 metres north to south, and a height of between 0.4 and 0.6 metres, suggest something that was once considerably more prominent. Three possible kerbstones, the shaped stones that would originally have edged and contained a cairn's outer margin, survive in a curved but non-contiguous line along the west to north-northwest edge, hinting at a structure that once held its form with more conviction.

What makes this particular spot quietly strange is that a modern drystone wall cuts straight across the eastern portion of the cairn, running north to south. The wall does serious administrative work: it marks the townland boundary between Glencolumbkille North and Killeenmacoog South, and simultaneously traces the barony boundary between Burren Barony and Inchiquin Barony. Barony boundaries in Ireland are old administrative divisions, many of which follow landscape features and older territorial lines of considerable age. Here, that boundary line simply marches over the ancient mound without ceremony, indifferent to whatever the cairn once meant to the people who raised it. The plateau itself is karst, the distinctive limestone terrain of the Burren, characterised by bare rock pavements, thin soils, and a tendency to preserve things beneath the surface even when the surface itself has been disturbed. The cairn slopes slightly to the north with the mountain, and the flat top sits fractionally higher at the southwest.