These sites, found in their thousands across Ireland, are thought to be prehistoric cooking places, typically consisting of a mound of fire-cracked stone accumulated beside a trough into which water was heated by dropping in stones from a fire. The stones, once used, shatter and blacken, and over centuries the discarded fragments build up into the low, horseshoe-shaped mounds that survive on better-preserved sites. At Killawillin, what remains is more modest: a scatter of that same burnt stone, turned up by agricultural work and spread across tillage ground.