Most examples follow a fairly predictable pattern: a stone-built flue channelling heat beneath a drying floor. The three kilns uncovered at Ballygrennan in County Limerick did not follow that pattern at all. Excavated from beneath pasture land on the boundary between the townlands of Ballygrennan, Goat Island, and Uregare, they were described by the excavating archaeologist as simply unusual, a word that tends to carry more weight in a site report than it might elsewhere.

The kilns came to light during monitoring of topsoil-stripping, the kind of careful watching brief that precedes ground disturbance on sites of archaeological sensitivity. Emmet Byrnes excavated all three under Licence 02E0368, and his findings, published in 2004, recorded oval features dug directly into the earth, ranging from 2.7 to 5.5 metres in length and between 1.2 and 2 metres wide, with depths of only 22 to 27 centimetres. The sides and base were partly lined with stone flags, but crucially, none of the three had a defined flue, the channel that in conventional kilns draws heat through the structure. Corn-drying kilns were a common feature of medieval Irish agriculture, used to dry harvested grain in a climate ill-suited to reliable open-air drying, but the absence of any flue here sets these apart from the standard form. Carbonised grains recovered from all three features were provisionally identified as bread wheat and barley. The kilns formed the third phase of activity within a broader medieval field system identified at the same site, placing them in a landscape that had been organised and worked for some considerable time. The nearby site of Uregare Church lies roughly 300 metres to the south-west, suggesting this was a settled, functioning agricultural community during the medieval period.

Because the monument has been fully excavated, there is nothing visible above ground today, and the site does not appear on aerial imagery. The land is now pasture, sitting immediately north of the road that marks the townland boundary with Goat Island. For anyone with an interest in medieval agriculture or the archaeology of the Irish midlands and west, the significance lies not in what can be seen but in what the excavation record preserves, a small and quietly puzzling cluster of features that did not quite fit the established type.