It measures roughly 16 metres north to south and almost 13 metres east to west, standing about a metre high, with an opening of nearly five metres facing west. That shape, and the material it is made of, are the giveaway: this is a fulacht fia, an ancient cooking site built up over repeated use from cracked, fire-shattered stone and charcoal-darkened earth.

Fulachta fiadh, the plural form, are among the most common prehistoric monuments in Ireland, yet they remain quietly puzzling. The conventional interpretation is that they functioned as outdoor cooking places, where water held in a timber- or stone-lined trough was heated by dropping fire-cracked stones into it until the water boiled. The mound itself is simply the accumulated waste from that process, stones that could not be reused piling up around the trough over time. What makes Ballyhoolahan worth singling out is not any one site but the sheer density of them. A researcher named Bowman, writing in 1934, recorded nineteen fulachta fiadh within this single townland alone. The mound described here sits only about thirty metres from a second example, and both are part of that larger cluster, suggesting that this particular stretch of north Cork was used with some intensity, across what may have been a considerable span of prehistoric time.