A fulacht fia typically consists of a mound of fire-cracked and burnt stones accumulated beside a trough or pit, thought to have been used for heating water, possibly for cooking, bathing, or industrial processes such as dyeing or brewing. What makes these sites strange is the sheer repetition of the activity they represent: stones were heated in a fire, dropped into a water-filled trough until it boiled, and then discarded into a growing heap beside it, a process repeated over and over across many generations.

The Kerry example was recorded by Cuppage in 1986 as an irregular, roughly kidney-shaped, grass-covered mound of burnt and fire-shattered stones measuring 12.4 metres northwest to southeast and rising to a maximum height of 1.75 metres. At its west-southwest side, a depression survives that appears to have been revetted, meaning its sides were lined and reinforced with upright stones, some of which remain standing while others have since collapsed inward. That stone-lined hollow almost certainly represents the trough where water was once heated. The mound itself is the accumulated by-product of that work, centuries of discarded, heat-fractured stone gradually building into the low grassy ridge visible today.