It sits in the catalogue of Irish heritage sites as a kind of gap, a named place with a designated record but no accompanying detail to explain what it was, when it functioned, or what, if anything, remains of it today.

Mills were once a fixture of the Irish rural landscape, and Cavan, with its abundant small rivers and streams fed by the drumlin country of Ulster's southern edge, had no shortage of them. A mill in this context would most likely have been a horizontal or vertical watermill used for grinding grain, though some rural mills were adapted for other purposes such as scutching flax during the linen industry's expansion through the eighteenth and nineteenth centuries. Without further detail on the Darkley site, it is impossible to say which type this was, when it was built, or who owned and operated it. The record exists; the story behind it does not, at least not yet in any accessible form.