The cairn is substantial, roughly 18 metres in diameter and about 3 metres high, and though it is now largely covered in grass and heather, the underlying mass is stone. A townland boundary wall cuts east to west straight across its top, treating the ancient monument as simply another feature of the landscape to be divided around.

The cairn is thought to be a passage tomb, a type of megalithic monument in which a stone-lined corridor leads inward to a central burial chamber, often oriented toward a significant point on the solar calendar. On Corn Hill, that interior was reportedly uncovered sometime in the early decades of the twentieth century. Then, in the 1960s, the chamber was apparently reopened and subsequently filled back in with stones, a sequence of events recorded by the archaeologist Michael Herity in 1974. Whether the original discovery produced any finds or observations that were properly recorded is not clear from what survives. An Ordnance Survey trigonometrical pillar, used in mapping, now sits on the cairn's surface, adding a third layer of human intervention to the mound. A second cairn lies approximately 120 metres to the south-west, suggesting this hilltop was a significant place in the prehistoric landscape, and a third has been noted in the area, though its precise location has not been confirmed.