At Dromdeer in County Cork, a fulacht fia, one of Ireland's most common yet still not fully understood prehistoric monument types, is recorded not through any visible earthwork or upstanding masonry but simply through a spread of burnt material noted by local sources. Stand in the field today and you would see nothing at all.

Fulachtaí fia, found in their thousands across Ireland, are the remnants of ancient cooking or processing sites, typically identified by a horseshoe-shaped mound of fire-cracked stone and charcoal, the debris left behind when stones were heated in a fire and dropped into a water-filled trough to bring it to the boil. They are most commonly associated with the Bronze Age, though their precise function has been debated for decades. Some researchers have proposed uses ranging from food preparation to textile dyeing or bathing. The Dromdeer example fits a pattern that is, in truth, more common than the well-preserved examples might suggest: centuries of ploughing, drainage, and land improvement have reduced many such sites to little more than a discolouration in the soil or a scatter of heat-shattered stone. Here, even that is barely perceptible, surviving only in local memory and in the word of whoever first reported the burnt spread to the record.