It is made not of earth but of burnt and fire-cracked stone, the characteristic signature of a fulacht fia, an ancient outdoor cooking site. The mound measures roughly ten and a half metres north to south and just over fifteen metres east to west, with a drain running along its straight southern edge. These structures are among the most common prehistoric monuments in Ireland, typically Bronze Age in date, and thought to have worked by heating stones in a fire and dropping them into a water-filled trough until the water boiled, serving as a cooking facility or possibly for other purposes such as bathing or textile preparation.

What makes the site at Ballyhoolahan quietly remarkable is not the mound itself but its company. In 1934, a researcher named Bowman recorded no fewer than nineteen fulachta fiadh within this single townland, suggesting that the area saw repeated, concentrated use over a long period. A townland is one of the smallest administrative land divisions in Ireland, typically covering a few hundred acres at most, so nineteen such sites in one place is a striking density. Whether this reflects a particularly favourable landscape, proximity to reliable water sources, or sustained seasonal activity over generations is not certain, but the cluster points to something more than casual, passing use.