And sometimes it offers a small, fire-reddened hole in the ground and a handful of questions that stay unanswered. At Barnahely in County Cork, what survives in the record is precisely the latter: a shallow circular pit, roughly three quarters of a metre across, its soil scorched and its interior packed with charcoal and ash, with no accompanying structures to explain what it once served.

The pit came to light in 1996 during archaeological test-trenching carried out ahead of factory construction, the kind of precautionary investigation that routinely precedes development on Irish soil. Excavated and reported on by O'Donovan, the feature was small but distinctive, its fire-reddening suggesting repeated or sustained burning rather than a single accidental event. More puzzling were the objects found nearby: a millstone and two incomplete millstone fragments. Millstones are workmanlike things, shaped to grind grain, and their presence implies some milling activity in the area, possibly connected to a horizontal or vertical mill that has left no other trace. Yet no walls, no post-holes, no structural remains of any kind were found that could be linked to the stones. Subsequent monitoring of the site produced nothing further, leaving the pit and the millstones as isolated clues without a surrounding context to make sense of them.