Its eastern-facing front elevation stands 3.15 metres high and stretches 5 metres wide, with random-rubble walls enclosing an earthen core across a footprint of roughly 7 metres east to west and 6 metres north to south. A lintelled corbelled recess, where the draught arch at the base of the kiln allowed workers to rake out the burnt lime, measures 1.6 metres high, 2.2 metres wide, and 1.4 metres deep, finished at the back with sloping slabs. Above it, a stone-lined funnel tapers upward into the body of the structure.

Lime kilns like this one were a commonplace feature of the Irish countryside from at least the seventeenth century through to the early twentieth, used to burn limestone at high temperatures and produce quicklime for agricultural liming of acidic soils and for use as mortar in construction. The process was straightforward but labour-intensive: limestone and fuel, usually coal or wood, were loaded in alternating layers through the top of the funnel, fired from below through the draught arch, and the resulting quicklime was drawn out through that same low recess once the burn was complete. Building the kiln into a hillside, as was done here, was standard practice; it allowed carts to tip limestone directly into the top without complex lifting gear, and the earthen bank provided natural insulation to sustain the heat. The Glenaknockane example follows this logic precisely, its orientation and construction reflecting generations of accumulated practical knowledge rather than any formal engineering.