What the plough disturbed was the remnant of a fulacht fia, one of the most common prehistoric monument types in Ireland and yet one that most people have never heard of. The term refers to a cooking site, typically Bronze Age in date, built around a trough dug into wet ground and filled with water. Stones were heated in a nearby fire and then dropped into the trough to bring the water to a boil, leaving behind a characteristic mound of fire-cracked, blackened rock. It is that scorched debris, accumulated over repeated use, that tends to survive in the archaeological record long after the wooden trough itself has rotted away.

The site at Carhoogarriff fits the pattern well. Fulachtaí fia, as the plural goes, are very often found in low-lying or marshy ground, where a reliable water source was close at hand, and the boggy conditions here would have been well suited to that purpose. The detail that a large spread of burnt material became visible during ploughing suggests the mound had already been reduced or disturbed before it was formally recorded, a fate common to many such sites across the country as agricultural improvement from the mid-twentieth century onwards brought machinery into fields that had lain relatively undisturbed for millennia. The specific location, on a south-south-west-facing slope, may reflect a practical preference for ground that drained in a particular direction, or simply where wet ground and fuel happened to coincide.