It is a quoin stone, one of the dressed corner blocks that give a wall its solidity and alignment, and it was built into that position when the church went up in 1826. What makes it quietly remarkable is what it was before: part of the base of a medieval memorial cross, bearing a Latin inscription cut in relief that records the piety of two named individuals. It sits roughly six feet from the ground, two of its faces exposed to the weather, one blank and one legible.

The inscription was recorded by Hogan in the early 1880s, who took a rubbing from the stone. It reads, in translation, as a request to pray for the souls of Richard Comerford, of Ballybur, Knight, and of his wife Mary Purcell, who together had the cross erected in honour of the Holy Cross of Our Lord, dated 20 July. The year of erection was never carved, and Hogan noted something stranger still: the space where a date might have gone appears to have been deliberately left blank, or even sunk down, as though the omission was intentional rather than accidental. The date can nonetheless be inferred. Richard Comerford died in 1637, and cross must have been commissioned at some point after his marriage to Mary Purcell and before his death. The left corner of the stone has since broken away, taking with it the opening word of the inscription and part of Richard's name, though the meaning remains recoverable. The cross-base is now embedded in cement render, and has been given a raised render surround, marking it out from the wall around it even as the wall itself has changed.