It is an easy feature to overlook, and its precise relationship to a second furnace recorded nearby remains unresolved, but together they point to an industrial operation that was, by sixteenth-century standards, considered notably productive.

The iron works were associated with Burrishoole Dominican priory, and they appear in the documentary record for the first time in 1580, when Sir Nicholas Malby, then Governor of Connacht, compiled a list of the abbey's assets. Among them he noted, with some emphasis, that it possessed "a very plentiful iron mine." The priory itself, founded in the fifteenth century, would have had both the institutional organisation and the landholding to sustain a smelting operation of this kind. Smelting furnaces of the period used charcoal-fired hearths to reduce iron ore into workable metal, a process that required substantial fuel, water management, and skilled labour. By 1837, the topographer Samuel Lewis was recording the ruins of the furnace on that sliver of land between the two lakes, and noting a second one at the old abbey, though he offered no further detail. Where exactly the abbey's own iron works stood has never been established with certainty, and no later source appears to have resolved the question.