A fulacht fia, the term used for a type of prehistoric cooking or industrial site found widely across Ireland, once left enough of a mark to be recorded as a mound on the Ordnance Survey six-inch map of 1937. By the time anyone looked again, there was nothing left to see. No raised ground, no scorched earth, no scatter of heat-shattered stone. Just grass.

Fulachta fiadh, the plural form of the term, are among the most commonly found prehistoric monuments in Ireland. They typically consist of a horseshoe-shaped mound of fire-cracked stone and dark, charcoal-rich soil built up around a trough, which was used to heat water by dropping stones heated in a nearby fire into a water-filled pit. They date broadly to the Bronze Age, though examples from other periods are known. The Rossline site belongs to a small local cluster of three, two of which have their own records. The fact that they appear together is not unusual; fulachta fiadh are often found in groups, sometimes near watercourses or low-lying ground. What is unusual here is the completeness of the disappearance. The 1937 map shows a mound; decades of ploughing or soil movement have since levelled it entirely.