A rath is a ringfort, a type of enclosed farmstead common in early medieval Ireland, typically defined by an earthen bank and ditch. What lay within this one was stranger than the usual finds: a narrow, stone-lined trench, barely a metre and a half long and half a metre wide, that the excavators thought was probably a kiln, while noting it did not resemble any kiln type they knew.

The excavation took place in 1950, led by Ó Ríordáin and Mac Dermott, who recorded the feature in detail. The trench was roughly rectangular, cut to a depth of around 0.6 metres, with upright stones forming its sides. At its eastern end, two lintel stones were still in place, suggesting it had once been partially covered. The fill contained charcoal and small fragments of burnt animal bone, evidence of heat and of organic material, though not enough to say precisely what process was being carried out there. A kiln in general terms is a structure used to apply sustained heat, whether for drying grain, firing pottery, or processing lime, but this example fits none of those familiar categories neatly. That the excavators published their uncertainty alongside their interpretation is itself quietly notable; the structure was recorded honestly as something understood only in outline.