Croom, in County Limerick, offers none of that. What it does offer is a document, and a question, and a long silence where the stonework should be.

In 1310, Croom was awarded a murage grant, a royal licence permitting a town to levy tolls on goods passing through in order to fund the construction of defensive walls. Such grants were a relatively common instrument of medieval urban policy in Ireland, and their existence usually implies at least an intention to build. The Irish Record Commission noted the Croom grant as far back as 1829, and it has been referenced in the scholarly literature since. But according to research compiled by Bradley and colleagues in 1989, it is not known whether any defences were ever actually constructed, and no physical traces of walls or gates have been identified on the ground. The grant is real; the walls, if they ever rose at all, have left no mark.

For a visitor, this is an unusual kind of site to seek out, one defined entirely by absence. There is nothing specific to locate or photograph, no scheduled monument to stand beside. The interest lies instead in walking the town with the question in mind: did the burgesses of fourteenth-century Croom collect those tolls and build something, or did the project stall, as many did, through lack of funds or shifting priorities? The town itself, situated on the River Maigue, retains other medieval traces worth attention, and the absence of walls does not diminish the place so much as complicate it. Sometimes what a town did not build, or could not build, tells you as much about its medieval circumstances as any standing ruin would.