Look more closely, though, and the logic of its construction becomes apparent: the depression was deliberately chosen so that the hillside itself could bear part of the load, and the random-rubble sandstone walls, packed around an earthen core, were built to withstand sustained, intense heat.

Lime kilns were once a fixture of the Irish agricultural landscape. The process involved burning limestone at high temperatures to produce quicklime, which farmers then spread on fields to reduce soil acidity and improve fertility. This example in Kilcolman Middle follows a design typical of the tradition. The north-facing front elevation stands roughly four metres high and extends over six metres wide. At its centre is a corbelled recess, a recessed arch formed by stones projecting inward in overlapping courses rather than shaped into a true arch, capped with a lintel and measuring roughly 2.3 metres in both height and width. At the rear, sloping slabs led to a stoking hole where fuel was fed into the fire, and a narrow rectangular opening at the base, just over half a metre wide, allowed the burnt lime to be raked out once firing was complete. The funnel at the top, through which limestone would have been loaded, is now infilled, and the side walls have partially collapsed, but the essential form of the structure survives well enough to read clearly.