It measures roughly fourteen metres across in both directions and rises to about 0.7 metres, shaped like a broad letter D when seen from above. To the untrained eye it might read as a slight rise in the ground, a natural irregularity in a farmer's field. It is neither. It is a fulacht fia, and once you know what you are looking at, the countryside around Cork starts to seem full of them.

A fulacht fia is a prehistoric cooking site, the remains of a system in which stones were heated in a fire and then dropped into a water-filled trough to bring it to the boil. The shattered, heat-stressed stones were raked out after use and piled to one side; over many uses, across many years or even centuries, those discarded stones accumulated into the horseshoe or D-shaped mounds that survive today. The proximity to a stream, as here at Ballyvodane, is entirely typical. Running water was essential to the process, whether the trough was cut directly into the ground and relied on groundwater seeping in, or was lined with wood or stone and filled by hand. Ireland has one of the highest concentrations of these sites anywhere in Europe, with the greatest numbers in Munster, and Cork in particular is exceptionally well supplied with them. Most date to the Bronze Age, roughly 1500 to 500 BC, though some sites show evidence of use over long periods. The mound at Ballyvodane, sitting on the northern bank of its stream and now surrounded by cultivated ground, fits the classic pattern closely.