It is the trace of a fulacht fia, a type of prehistoric cooking site found in considerable numbers across Ireland, particularly in low-lying, waterlogged ground near water sources. The name, sometimes translated loosely as "burnt mound", refers to the characteristic crescent or horseshoe-shaped mounds left behind when heated stones were repeatedly used to boil water, cracking in the process, and then discarded. Thousands of these sites have been recorded across the country, yet each one represents a small, specific moment of repeated human activity, probably spanning generations.

The typical fulacht fia works on a straightforward principle. A trough, often timber-lined or cut into the earth, would be filled with water. Stones were heated in a nearby fire and dropped into the trough to bring the water to a boil, whether for cooking, textile processing, or other purposes that archaeologists continue to debate. The broken, heat-shattered stones accumulated beside the trough over time, forming the mound that survives today. At Ardrah, the site sits beside a stream, which is entirely consistent with this pattern; proximity to running water was a practical necessity. The reclaimed nature of the surrounding pasture suggests the land has been significantly altered since the site was in use, making the survival of even a spread of burnt material worth noting.