The structure is modest almost to the point of invisibility: a low bank of earth and stone, roughly half a metre high and between two and four and a half metres wide, enclosing a flattened sub-circular area about five metres across. A modern path clips through its northern edge, which has obscured part of the ring, but enough survives to make out what was once a carefully prepared working floor.

This type of feature is known as a hearth platform or pitstead, the levelled area on which charcoal burners, sometimes called colliers, would construct their slow-burning mounds of stacked and covered timber. The process required days of careful tending, and the workers would often camp nearby for the duration. Woodland sites like this were chosen deliberately: a south-facing slope offered some shelter and warmth, while a level patch at its foot provided the stable, compacted ground needed to build and monitor the burn. The Trooperstown site sits in what is described as historic woodland, suggesting the trees here have been managed over a long period, likely in part to supply exactly this kind of industrial process. Charcoal production was essential for ironworking and other crafts long before coal became widely available, and platforms like this one were once scattered through wooded areas across Ireland and Britain, though relatively few have been formally recorded.