It is not much to look at, barely a metre above the surrounding land, but the mound is the remains of a fulacht fia, a type of prehistoric cooking site found in considerable numbers across Ireland. The basic principle involved heating stones in a fire, dropping them into a water-filled trough until the water boiled, and using that trough to cook meat. Over repeated use, the spent and shattered stones were piled up into the horseshoe-shaped or irregular mounds that survive today, often in low-lying, waterlogged spots chosen precisely because water was readily accessible.

The mound at Termons, known locally as Ardnawillan, measures eleven metres east to west and rises to a maximum height of 1.1 metres. It is largely composed of that characteristic burnt stone and is described as heavily overgrown. At its northern edge, facing the stream, an oblong depression measuring six metres by 1.5 metres most likely marks the position of the original trough where water was heated. What makes the site a little more interesting than a single example is the possibility that it is not alone. About thirty metres to the west, a low spread of burnt stone and blackened soil may indicate a second fulacht fia, though this area is less clearly defined. The site was surveyed and documented by A. O'Sullivan and J. Sheehan as part of their archaeological survey of the Iveragh Peninsula, published by Cork University Press in 1996.