During field survey work recorded by Gowen in 1999, two distinct spreads of burnt material were identified within the bog at Killoran, each one a low, inconspicuous remnant of a practice that was once commonplace across the Irish landscape.

A fulacht fia, in its simplest form, is a burnt mound, the accumulated debris of repeated fire-setting and water-heating using stones. The method involved heating rocks in a fire and dropping them into a water-filled trough until the water boiled, typically for cooking meat. The stones crack and shatter with the thermal shock and are discarded, building up over time into the characteristic horseshoe-shaped spreads that archaeologists find today. At Killoran, the material was composed mainly of sandstone, with some limestone and charcoal also present, an unremarkable mix in itself, though the combination of stone types can occasionally hint at what was locally available or specifically selected. Whether the two spreads represent separate episodes of use or broadly contemporary activity at the same location is not recorded.