Both arches are blocked now, which gives the structure a sealed, almost blank appearance, as though it has simply decided to stop explaining itself.

Lime kilns were the workhorse infrastructure of pre-industrial and early modern farming across Ireland. Stone was loaded into the top of the funnel-shaped chamber, alternated with fuel, and burned to produce quicklime, which could then be spread on fields to reduce soil acidity or used in mortar for building. The Aherla Beg example is a double kiln, meaning two such chambers were built side by side, presumably to increase output. The quarry setting is logical: the raw limestone was extracted directly on site and fed straight into the kilns without the need to transport it any distance. Of the two visible kilns, only the circular funnel of the southern one remains exposed at the rear, with a diameter of around 2.5 metres. At the northern end, there may be a third kiln, though overgrowth and later construction have made this difficult to confirm.

The blocked arches on the western elevation would originally have served as the draw holes, the openings at the base through which ash was raked out and the finished lime removed. Their closure, whether by deliberate infilling or gradual collapse and consolidation, is what leaves the structure looking so self-contained today. The quarry context means the kiln is partially integrated into the landscape rather than sitting free-standing in a field, which is itself relatively unusual and helps explain why it has survived as well as it has.