They appear as low, horseshoe-shaped mounds, typically found near water, and are generally dated to the Bronze Age, roughly 1500 to 500 BC. The mounds themselves are the accumulated debris of repeated burning and quenching: stones were heated in fire and dropped into a water-filled trough to bring it to the boil, shattering in the process and building up over time into the characteristic crescent shape. What they were actually used for remains genuinely contested. Cooking is the most widely accepted explanation, but brewing, textile processing, and even bathing have all been proposed with reasonable supporting arguments. The one at Kilfallinga, in County Kerry, is a quiet local example of this widespread but still puzzling tradition.

Kerry has a particularly dense concentration of these monuments, which is partly a reflection of the county's boggy, well-watered landscape, the kind of terrain where fulachta fia tend to cluster. Kilfallinga itself is a townland in the Kerry interior, and like many sites of this type it would be easy to walk past without recognising what the low rise in the ground represents. Beyond its presence in the townland and its classification as a fulacht fia, the specific details of this site, its dimensions, its state of preservation, any finds associated with it, remain undocumented in publicly available sources at present.