It is, in fact, a surviving piece of a front panel from a 16th-century chest tomb, a type of raised box-shaped funerary monument common to late medieval Ireland, and it has spent at least two centuries doing a rather different job from the one it was made for.

The fragment is composed of fossiliferous limestone, a material flecked with the compressed remains of ancient marine organisms, and it is decorated with six pointed niches, each containing foliate motifs carved in false relief, meaning the design creates an impression of depth without being fully three-dimensional. The base of the panel has been cut down, as has its left side, suggesting it was trimmed to fit its current secondary use. That reuse happened no earlier than 1804, when the cross wall into which it is now set was constructed. Whether the stone was already loose in the graveyard at that point, or dismantled from a tomb that had stood elsewhere on the site, is not recorded. A related fragment, possibly from the same original monument, has been identified separately, hinting that more of this tomb may survive in scattered form around the church grounds.