That small inversion is not an accident or a later addition; the text and the cross were cut as one piece, deliberately oriented so that the head of the cross, and the words above it, face east rather than west. This makes the slab genuinely anomalous. The overwhelming convention for such monuments is to place the cross head to the west, and scholars have noted this particular stone as exceptional precisely because it breaks that rule.

Inis Cealtra, a small island in Lough Derg on the Shannon, was one of the more significant early Christian monastic sites in Munster, and its graveyard preserves a remarkable concentration of carved slabs. This one lies just south of a composite grave, a burial feature made up of more than one structural element, and sits within a few metres of the wall of Teampul na bhFear nGonta, one of several churches on the island. The slab itself measures roughly 1.55 metres in length and 0.5 metres in width. Its Latin cross is carved in relief on a trapezoidal base with concave sides, a form that Macalister, writing in 1916 and 1917, classified as twelfth-century in type. Above the cross, filling the full width of the slab, is a panel carrying two lines of text in Irish. When Macalister recorded it in 1916 the inscription was still largely legible, reading OR DO CATHGAL, an abbreviated form of the Irish phrase oróit do, meaning a prayer for, followed by the personal name Cathgal. Since then the top right corner of the slab has broken away, taking the opening of the text with it.

The island is accessible by boat from Mountshannon on the western shore of Lough Derg, and the Saint's graveyard sits among the cluster of ecclesiastical remains that make Inis Cealtra unusual even by the standards of Irish monastic archaeology. The slab itself is easy to miss among the other grave markers, but the inverted orientation of its inscription rewards a second look.