The fragments came originally from the Main Guard in Clonmel, one of the more architecturally significant buildings in the south of Ireland, and their presence in a Kilkenny depot is the kind of administrative accident that heritage conservation occasionally produces.

The Main Guard in Clonmel is a seventeenth-century structure, built around 1674 to a design attributed to Sir William Robinson, the Surveyor General of Ireland who also worked on the Royal Hospital Kilmainham. It served variously as a courthouse and civic building, and its arcaded ground floor is an unusual survival of that period of urban architecture in Ireland. The fragments now held at Leggetsrath were recovered during conservation and restoration works carried out in the 1990s by Margaret Quinlan, working on behalf of the Office of Public Works. Such projects routinely produce displaced material, stonework or decorative elements deemed too fragile or too damaged to be returned to the fabric of a building but too significant to discard. The OPW depot at Leggetsrath became their resting place, catalogued and held against some future use or study.