What is exposed at the tips of those eroding arms tells the story: layers of heat-shattered stones and charcoal-enriched soil, the unmistakable signature of a fulacht fia.

A fulacht fia is a Bronze Age cooking or heating site, typically identified by a horseshoe-shaped mound of fire-cracked stone built up beside a water source. The process involved heating stones in a fire, then dropping them into a water-filled trough to bring it rapidly to the boil. Repeated use shattered the stones, and the discarded fragments accumulated over time into the distinctive mound we see today. The Coomarkane example measures roughly nine metres east to west and five and a half metres north to south, rising to about 1.1 metres in height, with a three-metre opening facing south towards the stream. That southward orientation is typical, positioning the trough close to a reliable water supply. The site sits within a network of old field boundaries, in an area of cutaway bog where peat has been removed over generations, placing this ancient feature in a landscape that has seen continuous human shaping. Roughly forty metres to the south-east, a hut site has also been recorded, suggesting that the stream bank here was once a small focus of activity rather than an isolated spot.