Beneath the turf lies a spread of burnt material, the characteristic signature of a fulacht fia, one of the most common and yet still somewhat puzzling monument types in the Irish landscape. These are ancient cooking sites, typically Bronze Age in date, where stones were heated in a fire and then dropped into a water-filled trough to bring the water to a boil. The cracked and fire-shattered stones were discarded in a horseshoe-shaped mound around the trough, and it is that blackened, heat-fractured debris that survives and identifies the site today.

What makes the Laharan example quietly interesting is the relationship between the monument and its water source, a relationship now partly erased. A spring once rose immediately to the south-west of the site, its location recorded on the six-inch Ordnance Survey map of 1937, but drainage works have since removed it from the landscape. Local information suggests the mound itself predated that drainage, meaning the fulacht fia and its associated spring survived together into living memory before the hydrology of the field was altered. The pairing of burnt mound and spring is exactly what archaeologists would expect, since a reliable water source was essential to the whole process, and its loss here makes the site harder to read in the ground than it might once have been. Roughly sixty metres to the south-east, a second fulacht fia has been recorded, and paired or clustered examples like this are not unusual, suggesting repeated or communal use of a favoured spot over time.