That combination of modest circumstances and early Christian carving is part of what makes it worth attention. The stone, a conglomerate flecked with quartz pebbles, bears an incised Latin cross with expanded terminals enclosed within a circle roughly 26 centimetres across, and a smaller incised cross above it. A metal cross has since been inserted into the top, layering a more recent act of devotion onto an already long history of use.

The story of how it got here is unusually well documented for an object of this kind. Writing in 1908, a researcher named Power recorded the account of Roger Sheehy, the man who had actually found the stone, then around eighty years old. Sheehy described digging it up from a bog close to the Bansha road, roughly half a mile from Tobar Iosa, the holy well beside which it now stands. A second, smaller stone, described as a rude cross, was apparently found alongside it in the same bog; that piece has since disappeared entirely. The surviving cross-slab was subsequently moved to its present position just north of the well, where it occupies a small wayside shrine. A cross-slab, for those unfamiliar with the term, is simply a flat or upright stone bearing an incised cross, a common form of early medieval Irish religious monument. What makes this one quietly unusual is that its original context was not the well at all but a patch of bogland some distance away, making its present association with Tobar Iosa a matter of later arrangement rather than ancient continuity.