It is easy to overlook, and that is rather the point. Measuring just over three-quarters of a metre tall and less than half a metre wide, with very short arms and a shaft that broadens unevenly as it descends, it has none of the refined carving associated with the more celebrated monuments at Glendalough. What it does have is a quiet stubbornness, the look of something planted deliberately and left to weather on its own terms.

The cross sits within the broader ecclesiastical landscape of Glendalough, the valley in County Wicklow associated with the sixth-century monastic founder St Kevin, where a cluster of early medieval churches, round towers, and carved stones survive in varying states of completeness. Sevenchurches, the name given to this part of the valley, refers to the concentration of ecclesiastical remains in the area, of which St Mary's is one. The cross-slab itself was noted by Harold Leask in 1950, who recorded it as a rough cross roughly one foot ten inches high, fixed in its socket some ten feet west of the church, with arms that expand slightly and a shaft of irregular width. A later description by Healy in 1972 confirmed it as mica-schist, a locally occurring metamorphic rock with a faintly silvery, layered texture, and gave slightly larger dimensions, suggesting the stone had perhaps shifted or been remeasured differently across the decades. A drawing of the slab appeared in Robert Cochrane's detailed survey of the ecclesiastical remains at Glendalough, published in 1925 as part of a report by the Commissioners of Public Works, placing it within a tradition of careful official documentation that stretches back into the nineteenth century.

The cross stands close to the south-west corner of St Mary's nave, and visitors who know to look for it will find it a short distance to the west of the church wall. It rewards close attention rather than a passing glance, particularly in low, raking light that picks out the texture of the mica-schist and the slight irregularities of the carving.