Two metres wide, round-headed, and bearing the faint traces of diagonal line tooling, it may once have been a window or a tomb niche. The uncertainty itself is part of the interest: no one has settled the question, and the stonework sits in its later surroundings without giving much away.

The fragment is a remnant of a Cistercian abbey that formerly occupied this site, or ground very close to it. The Cistercians, a reforming monastic order whose Irish foundations multiplied through the twelfth and thirteenth centuries, typically built in dressed stone with an emphasis on restraint and regularity. What survives here is a single architectural element, possibly traceried, meaning it may once have carried an ornamental pattern of interlocking stonework within its opening. When the medieval abbey was eventually lost and a Church of Ireland building raised in its place during the nineteenth century, this piece was incorporated into the new fabric rather than discarded. Whether that was a deliberate act of preservation or simply a practical reuse of available good stone is not recorded.