The kiln at Raheenapisha is keyhole-shaped, a form well suited to its purpose: corn-drying kilns of this type used a long flue to channel heat from a fire bowl up into a circular drying chamber, where harvested grain would be spread to dry before milling or storage. In Ireland's damp climate, this was not an optional step but a practical necessity, and kilns of this design appear across the country from the early medieval period onward.

This particular example was uncovered during excavations carried out ahead of the realignment of the N76 Callan Road, with fieldwork conducted under licence by Archaeological Consultancy Services and reported by G. Hull in 2016. The kiln's circular chamber measured just 1.2 metres in diameter and sat only 0.2 metres deep. From there, a partially stone-lined flue ran roughly 3.4 metres to a globular fire bowl at the south-west end, widening as it went, the whole arrangement laid out in that distinctive keyhole profile. Whoever last used the kiln cleaned it out carefully, yet the fills that remained told a detailed story. Fragments of charred oak and hazel wood were recovered, along with deposits of charred cereal grain, predominantly oat, with smaller quantities of barley and wheat. A radiocarbon date taken from one of those charred oat grains produced a result calibrated to between AD 1020 and 1186, placing the kiln firmly in the eleventh or twelfth century. An enclosure of some kind sits roughly 100 metres to the north-east, hinting at a broader pattern of activity in the area during the same period, though the relationship between the two features remains unclear.