It is not the sort of structure that announces itself. The front wall, built from random rubble and standing close to three metres high and three and a half metres wide, faces north, and set into it is an arched recess, slightly off-centre to the right. That recess is the most legible part of what remains: roughly one and a half metres wide and just over a metre deep, it is partly filled now with dumped material. The rear of the kiln has been badly damaged and swallowed by overgrowth.

Lime kilns like this one were once common features of the Irish countryside and the edges of rural towns. They were used to burn limestone at high temperatures, producing quicklime that farmers spread on acidic land to improve fertility, and that builders mixed into mortar. The process was straightforward but labour-intensive, and the kilns themselves, typically a stone-lined bowl or draw kiln set into a hillside or backing onto rising ground, were often built to serve a local community rather than any industrial enterprise. The Rathmore example, tucked behind domestic buildings rather than sited in open farmland, suggests it served the town's immediate needs at some point in the past, though no specific date of construction is recorded.