It is not large, measuring roughly one and a half metres tall by less than a metre wide, but cut into its face is a Latin cross raised in high relief, its surface lifted about eight centimetres above the surrounding stone. That modest projection, just enough to catch raking light on a low afternoon, is all that remains legible of what was once a carefully worked piece of early medieval carving.

The slab stands in the south-west corner of the so-called Saint's graveyard on Inis Cealtra, the island more commonly anglicised as Inishcaltra, positioned a little over three metres from the south wall and just over two metres from the west. The scholar R. A. S. Macalister, writing in 1916 to 1917, catalogued it as number 43 in his survey and assigned it to a twelfth-century type, a classification based on the form of the cross and the manner of its carving rather than any inscription. A cross-slab is exactly what the term suggests: a flat or roughly dressed stone bearing a cross, used as a grave marker or devotional object, and common across early Christian sites in Ireland. The twelfth century on Inis Cealtra was a period of considerable activity; the island was already an established place of pilgrimage, associated with Saint Caimin and visited by figures including Brian Boru. Whether this particular slab marked a grave, commemorated a patron, or served some other purpose is not recorded.

Weathering has taken a toll since Macalister's time, and the relief that was already relatively shallow is now considerably softer. The slab remains in situ, set into the ground of the graveyard where it has likely stood for the best part of nine centuries.