The other face, still visible in the graveyard on High Island off the Connemara coast, reveals just how much decorative ambition could be packed into a piece of stone measuring less than seventy centimetres tall. That the builders of the church saw fit to incorporate an existing grave marker into their foundations tells its own quiet story about how successive generations of Early Christian monastics reused and built over what came before.

The slab is cut from garnet mica-schist and marks Grave 5, a burial identified as having two distinct phases. The headstone itself belongs to the earlier of those phases, predating the church, and the human remains in the grave have been dated to somewhere between the late ninth and the late tenth century, making them the earliest recovered from the island. The carving on the visible face is layered with some intricacy: a Latin cross in relief, with a tapering shaft and D-shaped terminals, surrounds a central roundel containing a Greek outline cross with expanded limbs, and over that a second, incised Greek cross with forked terminals. C-scrolls and small bosses fill the upper angles of the quadrants, a decorative detail shared with the adjacent headstone immediately to the south, and fretwork runs along the flanks of the shaft. The concealed western face and the top edge of the slab carry further incised crosses with forked terminals, meaning the carver decorated surfaces that, even before the church wall was built, may never have been easy to see.

High Island, known in Irish as Ardoileán, is a small uninhabited island roughly five kilometres off the Connemara coast and accessible only by arrangement with local boatmen, weather permitting. The monastic remains there include the church, graveyard, beehive cells, and other features clustered together on exposed Atlantic rock, and the cross-slab sits within that wider complex, its position in the graveyard marking it as central to the earliest phase of activity on the site.