Sixteen metres long, fourteen metres wide, and only half a metre high, it is partially overgrown and has been worn down further by cattle over the years. What remains is the accumulated debris of prehistoric cooking, the burnt and shattered stone that gives a fulacht fia its distinctive dark, crumbly character.

A fulacht fia is a type of ancient cooking site found in great numbers across Ireland, typically Bronze Age in date. The method involved heating stones in a fire and dropping them into a water-filled trough to bring it to a boil; the stones cracked and splintered with the thermal shock, and over repeated use the discarded fragments built up into the mounded shape that survives today. The waterlogged, low-lying ground at Coolineagh is exactly the kind of setting these sites favour, close to a reliable water source and sitting in terrain that would have held moisture. What makes this particular spot quietly notable is not the mound itself but its company: a second fulacht fia lies immediately to the south-west, making this a paired site, a reminder that these places were used and reused, perhaps across generations, and that prehistoric people returned to the same productive ground again and again.