It measures roughly fourteen metres north to south and fifteen metres east to west, which makes it a substantial feature on the landscape even if it reads, at first glance, as little more than a slight rise in the ground. This is a fulacht fia, one of the most common yet least understood monument types in the Irish archaeological record, and its setting beside running water is no accident.

Fulachtaí fia are prehistoric cooking or processing sites, typically Bronze Age in date, found in their thousands across Ireland. The usual interpretation is that stones were heated in a nearby fire, dropped into a water-filled trough to bring it to the boil, and used to cook meat or process other materials. The spent, shattered stones were then raked aside, building up over time into the characteristic horseshoe-shaped mound of burnt and fragmented rock that survives today. The proximity to streams at Garraun fits this pattern precisely; a reliable water source was essential to the whole operation. What once would have been an active, smoky, practical site is now absorbed into the ordinary rhythms of a Cork pasture, the mound persisting simply because broken burnt stone is of little agricultural use and so tends to be left undisturbed.