One of these sites shows a spread of burnt material, the characteristic signature of a fulacht fia, and it is this scorched evidence that marks it out as something more than an unremarkable patch of boggy earth.

A fulacht fia, sometimes called a burnt mound, is one of the most common prehistoric monuments in Ireland. The typical interpretation is that these were outdoor cooking sites: a trough dug into the ground and filled with water, heated by dropping fire-cracked stones into it until the water boiled, then used to cook meat. The shattered, fire-blackened stones were thrown aside after use, gradually building up into the low horseshoe-shaped mounds that survive today. They are found most often in low-lying or waterlogged ground, which is precisely the setting here. The marshy conditions at Aglish would have provided a ready water source, one of the basic requirements for the method to work at all. Most fulachta fiadh date to the Bronze Age, broadly speaking the period between around 2000 and 500 BC, though some sites have produced dates outside that range.

What makes the Aglish example quietly interesting is not any single feature in isolation but the fact that three companions sit with it in the same field. Groups of fulachta fiadh are known elsewhere in Ireland, and their proximity to one another may reflect a particularly favourable location, perhaps seasonal gatherings, or activity that returned to the same marshy ground across generations. The burnt spread recorded here is a small but legible mark of all that repeated effort.