It is the surviving remnant of a fulacht fia, a type of prehistoric cooking site found in great numbers across Ireland, typically consisting of a trough, a hearth, and a mound of fire-cracked stones that accumulated as hot rocks were used to boil water. Most fulachta fiadh date to the Bronze Age, though their precise function has been debated, with some researchers suggesting uses beyond cooking, including brewing or textile working.

What makes the Coolcloher site quietly telling is not what survives but what has been lost. A researcher named Bowman, writing in 1934, recorded three fulachta fiadh on land belonging to a D. Guerin in this area. By the time the site was formally documented, two of the three had already been levelled, leaving this single mound as the only one still readable in the landscape. The burnt material now exposed in the drain section is essentially an accidental cross-section of the mound's interior, revealing a depth of accumulated debris that would otherwise be invisible beneath the pasture grass.