It sits quietly in pasture on the western side of a road, built into a slope as if trying to avoid notice, and it is precisely this invisibility in the official record that makes it interesting. Structures like this were the workhorses of pre-industrial and early industrial agriculture across Ireland, yet many were never formally documented.

A limekiln is essentially a furnace for burning limestone at high temperatures to produce quicklime, which was spread on acidic farmland to improve soil fertility and also used in the making of mortar. This example at Carrigans dates to the mid or late nineteenth century, though it is considered post-1700 in origin. It is a rectangular structure, roughly 3.3 metres north to south and 5.4 metres east to west, with rounded corners and walls that incline slightly inward as they rise. The walls are built from random rubble limestone encasing an earthen core. The north-facing front elevation stands around four metres high and features a stone-lintelled recess, just over a metre and a half wide and nearly as tall, currently propped by a wooden pole. This recess steps down toward the rear, where a narrow rectangular opening sits at its base; this is the eye or draw hole, through which the burnt lime would have been raked out. The funnel above, where limestone and fuel were loaded from the top, is now filled in, though a circular depression two metres across and roughly one and a half metres deep still marks its position. A low earthen ramp at the rear would have allowed workers to load material down into the funnel from above. A small yard in front of the recess is defined by a scarp to the east and a stone wall to the west, the remnants of the working space around the kiln's mouth.