It is an unremarkable position for a piece of stone that was once, most likely, part of an arched doorway or window opening in a medieval building somewhere in Cashel.

The fragment measures 0.85 metres in length and carries several features that identify it as dressed architectural stonework. A chamfered edge, that is, a flat face cut at an angle to soften what would otherwise be a sharp corner, runs along one side and curves at its upper end, preserving what masons call the spring of an arch, the point where a curved opening begins to rise from its vertical support. The stone also shows punch dressing, a technique in which a pointed tool was used to work the surface into a finely textured finish, and a drafted margin, a smooth border chiselled around the edge to frame that texture. These are the marks of deliberate, skilled work. The buttresses at the rear of O'Brien's hostel, a converted outbuilding roughly 200 metres north-east of Hore Abbey, a Cistercian monastery founded in the thirteenth century, were built from salvaged stone, and this jamb ended up horizontal in the most westerly of the two, set about 0.35 metres above a ground level that drops away by roughly a metre beside the outbuilding. Where exactly it came from is not known, though the most plausible answer is simply: somewhere in Cashel, a town whose medieval building stock was once considerably greater than what survives above ground today.