Among the remains is a broken cross-base, a roughly quadrangular slab of garnet mica-schist measuring just under half a metre in length, that has spent decades quietly migrating around the interior of the island's ruined church. In 1984 it was recorded near the north side of the doorway; by the 1990s, someone had moved it to the altar against the east wall. It is now no longer on the island at all.

The slab is understood to be a cross-base, the footing into which a standing stone cross would once have been socketed, though the socket itself is incomplete because of the break in the stone. Whether a cross ever actually stood in it is a question that leads back to a drawing made in 1839 by the antiquarian William Wakeman, which appears to show a cross at the site that has since disappeared entirely. The stone itself is undecorated, a plain slab with no carving or inscription, which makes the Wakeman drawing the closest thing to evidence that it ever held anything upright. The cross-base has since been transferred into the care of the Office of Public Works and is held at their depot in Athenry, County Galway, removed from its island context and stored some forty kilometres inland.