It was not found here. It was placed here, in 1869, by a man named Kinahan, having been recovered from debris within the monastic enclosure to the north. That act of repositioning, well-intentioned as it presumably was, means the slab now occupies a kind of limbo, roughly 6.5 metres south of the island's early medieval church, set between two boundaries it was never originally meant to mark.

The stone itself is garnet mica-schist, a metamorphic rock with a faintly glittering surface, and it carries carvings on both faces. The southern face is the more elaborate of the two: an expansional cross, meaning one whose arms flare outward toward their ends, with D-shaped terminals and a central roundel, all worked in low relief. A small raised boss survives in the upper left quadrant. The right terminal has broken away and the top one is damaged, so what reads as a composition now is already a fragment of what was once there. The northern face is quieter and considerably more worn, bearing a linear cross with forked terminals, the kind of carving that rewards patience and a raking light. High Island, known in Irish as Ard Oileán, was home to a monastic community in the early medieval period, and cross-slabs of this type, upright stones incised or carved with a cross, were a common form of devotional or commemorative marker in such communities along the western seaboard. That two of them ended up buried in rubble within the enclosure suggests a long period of abandonment and collapse before anyone thought to record them.