It measures roughly ten metres east to west and four metres north to south, rising only about seventy centimetres above the surrounding ground, which is modest even by the standards of its type. A drain cuts through it, and tree planting has disturbed its edges, yet enough of the original mass survives to confirm what it is.

This is a fulacht fia, a term used by archaeologists for a particular kind of Bronze Age cooking or processing site found in extraordinary numbers across Ireland. The name translates loosely as "cooking pit of the deer," though the full range of activities that took place at these sites is still debated. The typical arrangement involved a trough, often timber-lined, filled with water and heated by dropping fire-cracked stones directly into it. The stones, once spent and shattered by repeated thermal shock, were raked aside and accumulated over time into the characteristic horseshoe-shaped mound that survives at Ballynagree. Thousands of these monuments are recorded across the country, making them one of the most common prehistoric site types in Ireland, yet most remain as quietly anonymous as this one, buried under improved farmland, bog, or, as here, plantation forestry.