The combination is not as contradictory as it might first appear. Early Irish monasteries and church settlements were often self-sufficient communities, and the working of metal, whether for tools, fittings, or liturgical objects, was a practical necessity that could share ground with devotional life. Even so, finding firm physical evidence of it inside the enclosure boundary gives the site a particular texture.

The evidence came from excavations carried out in the south-western quadrant of the enclosure at Caherlehillan, which forms part of a broader complex of early ecclesiastical remains in the area. Smelting refers to the initial extraction of iron from ore using intense heat, while forging is the subsequent shaping of the raw metal by hammering. Both processes leave recognisable traces in the archaeological record, including slag, heat-affected soils, and the remains of furnace structures. The work at Caherlehillan was documented across a series of publications by Sheehan between 1997 and 2004, which together build a picture of industrial activity folded into what was primarily a religious site.