Lime kilns were industrial furnaces used to convert limestone or other calcium-rich rock into quicklime by burning it at high temperatures; the resulting material was spread on acidic agricultural land to improve soil fertility, or used in construction as mortar and plaster. This one is substantial, with a front wall of random rubble sandstone rising to roughly five metres, pierced by an arched recess nearly two and a half metres wide and over a metre and a half tall, with an inner flat arch and sloping slabs set to the rear.

The kiln was associated with the adjacent Carraundulkeen Quarry, which would have supplied the raw stone. The standard design is clearly visible here: three horizontal ledges cross the face of the front wall, and a ramp at the rear gave workers access to the top of the structure, where stone and fuel were loaded down into the funnel, which measures roughly two metres in diameter. Once lit, the kiln could burn continuously for days, with the calcined lime drawn off from the arched opening at the base. The front wall was also extended northward at some point to form one side of a lean-to structure alongside the kiln, suggesting the site had more going on than burning alone, perhaps storage or shelter for those working it.