The site at Kilrussane came to light in 2001 during excavation ahead of the N8 Glanmire-Watergrasshill Bypass, and what it revealed was quietly remarkable: five bowl furnaces and a possible forging pit, representing a fleeting but complete episode of early metalworking preserved almost by accident in the soil.

Bowl furnaces are exactly what the name suggests, shallow clay-lined depressions dug into the ground and used to generate the intense, controlled heat needed for smelting. The Kilrussane examples were small, ranging from roughly 35 to 45 centimetres in diameter and no more than 16 centimetres deep, and all of them had been truncated, meaning their upper portions were gone. What remained was still richly informative: deposits of charcoal and iron slag within the furnace fills, and enough metallurgical waste to allow analysis. That analysis pointed to a specific process, the smelting of iron blooms from bog ore. Bog ore is a naturally occurring iron-rich deposit that forms in waterlogged ground, and it was a common raw material for early Irish smiths working far from any conventional ore source. Radiocarbon dating of two furnaces returned a range of 352 to 42 cal. BC, placing the activity squarely in the Irish Iron Age. The excavator, Sherlock, noted that the waste patterns suggested the whole cluster of furnaces may represent no more than a single season's work, a brief, concentrated effort rather than a long-established smithing tradition at this spot. A second metalworking site was recorded approximately 530 metres to the north-east, raising the possibility that this part of north Cork was, for a time, a locale with some significance for iron production.