The structure is built directly against an east-facing slope, a common approach that allowed the ground itself to support the kiln's walls and simplify the loading of raw limestone from above. The front face stands roughly three metres high and six metres wide, with an arched recess, the opening through which the burnt lime was raked out, measuring about 1.85 metres high, two metres wide, and two metres deep. That arched opening is large enough to walk into, and gives the structure an almost architectural quality that can catch a visitor off guard.

Lime kilns like this one were workhorses of rural Ireland from the seventeenth century onward, and many survived in use well into the twentieth. The process was straightforward but demanding: layers of limestone and fuel, usually coal or culm, were packed down into the funnel-shaped bowl at the top of the kiln, fired over several days, and the resulting quicklime extracted through the draw arch at the base. Quicklime had two main uses, often applied together: spread on fields to reduce soil acidity and improve yields, and mixed with water and sand to make lime mortar or whitewash for buildings. At Kilcor, the funnel has since been infilled, removing the most visible sign of how the kiln operated, but the draw arch and the broad front remain intact. A lean-to structure was added at some point against the front face, suggesting the kiln saw enough regular use to warrant some degree of shelter or storage alongside it.