Fragments of its old town wall still stand in places, and the ruins of Sweetman's Castle and the collegiate church of St Mary keep company with the living town around them. Somewhere among this layered fabric of stone is an architectural fragment, recorded and catalogued, that has caught the attention of those who document such things, though its precise character, whether a carved capital, a moulded doorway jamb, or some other dressed stonework displaced from its original context, remains undescribed in any publicly available form.

Architectural fragments of this kind are more common in medieval Irish towns than most people realise. They turn up reused in later walls, propped in corners, or incorporated into buildings whose builders valued a good cut stone over any concern for its origins. Thomastown was founded in the thirteenth century by Thomas FitzAnthony, a Welsh-Norman settler who gave the town his name, and it developed as a significant walled settlement with a market and a crossing point on the Nore. The density of medieval activity here means that carved or moulded stonework from any number of periods could plausibly have survived in secondary use, waiting for someone to notice it.