The mound they come from, a kidney-shaped grass-covered rise on the eastern bank of a tributary of the Drimminboy River, is a fulacht fia, a type of ancient outdoor cooking place found in considerable numbers across Ireland. The typical arrangement involved a trough filled with water, heated by dropping fire-cracked stones into it until the water boiled. The discarded, shattered stones were piled alongside, and it is these characteristic heaps of dark, heat-fractured material that survive as low mounds in the landscape. At Deelis, that mound measures eleven metres north to south and just over six metres east to west, rising to a height of around one and a quarter metres, with a distinct opening on its south-western face where the two arms of the kidney shape part.

What makes this particular site quietly compelling is not just its form but its slow disappearance. The Drimminboy tributary is actively eroding the tip of the western arm, and the burnt stones and charcoal that have been accumulating there for thousands of years are now being redeposited along the river-bed downstream. It is the kind of gradual, unhurried loss that does not announce itself: the mound still sits intact in the rough pasture on its gentle north-facing slope, still grass-covered, still legible as a structure. But the river is already working at its edge, and the scattered stones visible in the water below are a reminder that archaeological survival is rarely permanent, only postponed.