Cairns, in the Irish archaeological sense, are mounds of heaped stone, often raised over burials during the Neolithic or Bronze Age, and these two have endured quietly on the hillside while the distinctive cone of Sugarloaf behind them draws all the attention.

The pair differ noticeably in scale. The more northerly of the two is very low and modest, measuring around seven metres in diameter, and survives in a reduced state. The larger cairn, situated just to the south, is considerably more substantial, with a diameter of between thirteen and fifteen metres and a height of around one and a half metres. At its centre there is a hollow, the kind of depression that often indicates past disturbance or the collapse of a burial chamber beneath. Most striking, however, is a block of white quartz that remains visible within it. Quartz was no accident in prehistoric monument-building; at sites across Ireland, from Newgrange to smaller local cairns, white quartz appears to have carried deliberate significance, associated with light, ritual, or marking the dead. Whether that same intent lies behind the quartz block here cannot be confirmed, but its presence gives the larger cairn an unusual quality among the moorland grass.