Look more closely, though, and the horseshoe shape gives it away. This is a fulacht fia, one of thousands of Bronze Age cooking sites scattered across Ireland, and one of the more quietly evocative examples in County Kerry.

A fulacht fia typically consisted of a trough dug into the ground, filled with water, and heated by dropping fire-cracked stones into it until the water boiled. The broken, burnt stones were then piled to the side, accumulating over repeated use into the characteristic crescent or horseshoe mound that survives today. The example at Derrynacaheragh measures roughly nine metres northwest to southeast and 7.6 metres northeast to southwest, standing about 1.1 metres high, with its opening facing southwest. It sits in a sheltered hollow within a wider landscape that still retains traces of ancient field boundaries, suggesting this was once a more organised and inhabited place than the scrubby hill pasture now implies. A stream running nearby has cut through the northeastern edge of the mound, exposing some of the burnt material beneath the turf, offering an accidental cross-section through centuries of accumulated use.

The setting repays attention beyond the mound itself. The relict field boundaries surrounding the site hint at a Bronze Age farming landscape that has largely been absorbed back into the hillside, and the position overlooking the Feabunaun valley suggests the site was chosen with some care, close to water and sheltered from the prevailing weather.