The term fulacht fia, sometimes translated loosely as "cooking place of the deer," refers to a type of prehistoric burnt mound, typically a horseshoe-shaped heap of fire-cracked stone and dark, charred soil found near a water source. The standard interpretation holds that stones were heated in a fire and then dropped into a water-filled trough, bringing it rapidly to the boil, though debate continues among archaeologists about whether cooking was the sole or even primary function. Some researchers have proposed uses ranging from textile processing to bathing.

These sites date predominantly from the Bronze Age, roughly 1500 to 500 BC, though some examples have returned earlier or later dates. The characteristic mound shape forms gradually as cracked and spent stones are discarded to the sides of the trough after each use, building up over repeated episodes into the low, curved earthwork that survives today. They are so numerous in Ireland, particularly in the midlands and west, that they have sometimes been described as the most common field monument in the country, yet individually they attract little attention compared to megalithic tombs or ring forts. The Reaskaun example in Clare is one of many such sites catalogued across the county, sitting within a landscape that has been farmed and modified for millennia without entirely erasing what lies beneath or beside the fields.