To most eyes it would look like nothing more than a low, unremarkable rise in the ground. In fact it is the remnant of a fulacht fia, one of the most common yet still not fully understood archaeological monument types in Ireland, and it was nearly lost entirely in 1969 when, according to local memory, the mound was levelled.

A fulacht fia is, at its simplest, a prehistoric cooking site. The typical arrangement involved a trough filled with water, heated by dropping fire-cracked stones into it until the water boiled. Those spent, shattered stones were piled to the side after each use, building up over time into the horseshoe-shaped or spread mounds that survive today, often dark with charcoal and fire-reddened fragments. The Cloonsillagh example sits to the east of a spring, now dry, which would once have supplied the water essential to the whole process. That association between fulachta fiadh and natural water sources is so consistent across Ireland that the presence of a dried-up spring here is itself a small confirmation of what this place once was. The site dates in type to the Bronze Age, though precise dating for this particular mound is not recorded.

What the levelling of around 1969 left behind is a spread rather than a proper mound, the material disturbed and flattened but not removed entirely. The burnt stone scatter still visible beneath the pasture grass is, in a quiet way, a record of repeated use across what may have been centuries, each fired stone a discarded remnant of a meal or a process we can only partially reconstruct.