It is an easy thing to overlook, absorbed as it is into the landscape of the riverbank, but the structure repays a second look.

A lime kiln is a relatively simple industrial device, used to convert limestone or shell into quicklime by burning it at high temperatures. The resulting material was essential in pre-industrial rural Ireland, spread on fields to reduce soil acidity and mixed with water and sand to make mortar for building. The Reenmurragha example is compact but well-considered in its design. At the base of the front wall, a pair of low lintelled passages, each just 0.7 metres high and 0.5 metres wide, open into the structure. These are the draw holes, through which fuel and air were fed and through which the burnt lime was raked out once the firing was complete. Behind them, the interior opens into a square, stone-lined funnel roughly 2.5 metres across, with rounded corners, into which the raw limestone would have been loaded from above along with layers of fuel, typically peat or wood. The integration of the kiln into the existing retaining wall along the riverbank suggests a practical economy of construction, using the wall's mass for insulation and stability rather than building a freestanding structure from scratch. The riverside location would also have made transport of materials, whether incoming stone or outgoing lime, considerably more straightforward.