What first appeared during construction monitoring at Cherryville, County Kildare, was a scatter of darkened, circular patches in the earth, stained with charcoal and burnt clay. They might easily have been dismissed as minor disturbances, but excavation revealed something more deliberate: a cluster of bowl furnaces, the kind of simple pit-based smelting or metalworking structures used across Ireland and Britain from prehistory into the medieval period. A bowl furnace is essentially what it sounds like, a shallow depression cut into the ground, sometimes clay-lined, in which a fire could be sustained at high enough temperatures to work metal. The finds confirmed the identification: most of the furnace fills contained lumps of slag, the glassy waste produced when metal ore is smelted.

Excavated under licence by Thaddeus C. Breen, the site, designated Site 12, yielded eight bowl furnaces spread across the area, varying considerably in scale. The largest measured 1.75 metres in diameter and 0.5 metres deep; the smallest was a modest 0.35 metres across and barely 0.06 metres deep. One had an unusual figure-of-eight plan, effectively two conjoined bowls at different depths, perhaps reflecting a two-stage working process. A ninth feature looked similar but turned out to be too shallow and irregular to have functioned as a furnace, though it contained comparable material and was probably in use at the same time. Beyond the furnaces, the site grew more complex. Over 300 sherds of medieval pottery were recovered from a series of irregular linear features, likely the remnants of field boundary ditches, and a pair of bronze tweezers turned up in one of them. A stone-lined pit near the eastern edge of the site, with three narrow upright slabs forming one of its walls, added another layer of activity that did not fit neatly into the metalworking story. The features appear to belong to different periods, so what looks like a single industrial site is probably the accumulated trace of several distinct episodes of occupation and use.

The location is unremarkable today, absorbed into the modern landscape near Cherryville on the eastern fringes of Kildare. The site came to light not through targeted investigation but through the monitoring that accompanies ground disturbance during development works, the kind of archaeology that only exists because someone is watching when the machines move in.