It is easy to overlook, being less than a metre tall and only about ten centimetres thick, yet cut into its eastern face is a Latin cross rendered in relief, its arms angled slightly upward in a detail that gives it an oddly animated quality.

The slab is one of two in the vicinity bearing Latin crosses in what scholars describe as false relief, meaning the cross is raised from the surrounding surface rather than being incised into it. The architectural historian Harold Leask recorded this particular example in 1950, noting its dimensions with characteristic precision: roughly two feet eleven inches high, a foot and four inches wide, set approximately twenty feet west of the church gable. The site falls within the broader Glendalough ecclesiastical complex, known locally as Sevenchurches, a name that gestures at the cluster of early medieval religious remains gathered in the valley. An earlier published record of the slab exists in Robert Cochrane's detailed survey of the Glendalough remains, which appeared as part of the Eightieth Annual Report of the Commissioners of Public Works in Ireland, published in 1925, and includes drawn elevations of the stone.

The slab sits 7.1 metres west of the western gable of St Mary's Church, which gives a fairly exact target for anyone looking for it on the ground. The socket stone that holds it upright is itself worth noticing, suggesting the slab was intended as a permanent marker rather than simply propped in place. Whether it originally served as a grave marker, a boundary indicator, or something else connected with the liturgical life of the site is not recorded, and the slight upward tilt of the cross arms remains, for now, unexplained.