The pairing is not accidental. Lime kilns, stone-built furnaces used to burn limestone at high temperatures to produce quicklime, were essential to the agricultural economy of rural Ireland. Quicklime was spread on fields to reduce soil acidity, and it was also used in mortar and whitewash. Having one close to a working mill made practical sense in a landscape where labour and transport were precious.

What survives at Ballinglanna gives a reasonable sense of the kiln's original form. The front face retains an arched recess measuring 2.3 metres high and 2.9 metres wide, the opening through which fuel was fed and ash removed during firing. Above that recess, joist-holes are still visible in the stonework, the sockets that once held the timber frame of a lean-to structure, probably a simple shelter to keep fuel dry or to protect workers from the weather during the long hours a burn required. The rear of the kiln is no longer accessible, and the structure has partially collapsed, so the full bowl or pot where limestone was loaded from above can no longer be easily read. Even so, the front elevation preserves enough detail to suggest a reasonably substantial installation, one built to last rather than thrown up as a temporary measure.