The oddity is this: the 1842 Ordnance Survey six-inch map recorded only one kiln here, yet by the time the 1905 and 1935 surveys were made, both appeared. Whether the second was always there and simply missed, or was added in the intervening decades, is not entirely clear. Either way, the pair were built so seamlessly that their shared front elevation, rising to around 5.3 metres, shows no obvious break between the two recesses, making them read as a single structure at first glance.

A lime kiln, for those unfamiliar with the agricultural landscape of nineteenth-century Ireland, was essentially a furnace in which limestone and fuel were alternately loaded from the top and burned to produce quicklime, used to sweeten acidic soils or prepare mortar. The kilns on Quitrent Mountain follow a typical form: each has an arched opening at the base, known as the draw hole, through which the burnt lime was raked out, and a funnel above into which the raw materials were loaded. Both funnels here are slightly barrel-shaped, roughly two metres in diameter, stone-lined for most of their depth but finished with brick at the upper metre or so. The arched recesses are well-constructed, their southern example retaining neatly shaped voussoirs, the wedge-cut stones that hold a curved arch together. The random-rubble outer walls encase an earthen core across a footprint of roughly 13 metres north to south and 14 metres east to west. Two projecting ledges on the front face, at heights of 2.3 metres and 3.8 metres, would have provided working platforms for those loading the kilns from above.

The rear of the structure is overgrown, and both draw-hole recesses have partially collapsed, their interiors infilled with debris from the fallen cores and funnels. The kilns form the western boundary of a small rectangular field, tucked into the slope as though the hillside itself was pressed into service as part of the construction.