One of a pair of prehistoric standing stones, it was removed by the landowner at some point in the recent past, leaving behind a quiet absence where there had been a marker of the dead for thousands of years.

The stone was modest in scale, standing 1.37 metres high, and had been positioned approximately fifteen metres north of a cairn known as the Carrig cairn. Cairns of this type are prehistoric funerary monuments, mounds of stone raised over burials, and this one forms part of a broader cluster of prehistoric sites in the area. The standing stone itself marked a coarse urn pit burial, a type of Bronze Age interment in which cremated remains were placed in a ceramic vessel and buried in a pit in the ground. The pairing of a standing stone with such a burial was not uncommon in prehistoric Ireland; the stone likely served as a surface marker, making the grave visible across the landscape in a way that a pit alone could not. That two standing stones once occupied this ground suggests the site carried some deliberate ceremonial or commemorative arrangement, though the removal of one stone has made that relationship harder to read.

Blessington Reservoir, which the slopes here overlook, was itself created in the 1940s when the River Liffey was dammed at Poulaphouca, flooding a valley and submerging earlier field systems and settlements. The prehistoric monuments at Lugnagun predate that transformation by millennia, but the flooding reshaped the visual context in which they now sit, replacing a river valley with an open expanse of water that gives the hillside an unexpectedly open aspect.