The slab originated at Teampall Bhreacáin on the Aran Islands, one of the early medieval ecclesiastical enclosures on Inis Mór, but it has long since left Co. Galway and now sits in the Ulster Museum in Belfast, separated by some distance from the island site it once marked.

The carving itself is modest but deliberate. A Greek cross, a form with four arms of equal length, has slightly expanded terminals, meaning each arm flares outward at its tip, a detail common in early Christian stonework. This cross is set within a double circle, framing it neatly on the small rectangular face of the slab, which measures roughly 43 centimetres by 34 centimetres. Above the circle, a single Latin inscription reads CETHERNACH, a personal name that presumably identifies the individual for whom the stone was made, or perhaps a monk or cleric associated with the site. The name is otherwise unattested in connection with Teampall Bhreacáin, and no further biographical detail survives. Early Christian cross-slabs of this kind were typically grave markers or memorial stones, placed within or near a church enclosure to preserve a name within the community's memory and prayers.

Visitors hoping to see the slab will need to look not to the Aran Islands but to Belfast, where it is held in the Ulster Museum's collections.