These were the remains of a fulacht fia, one of the most common yet still somewhat mysterious monument types in the Irish archaeological landscape. A fulacht fia is, in essence, a prehistoric cooking site, typically consisting of a trough that would have been filled with water and heated using fire-cracked stones, which were repeatedly plunged in to bring the water to a boil. The cracked and discarded stones accumulate over time into a distinctive mound or spread, and it is these telltale fragments that the ploughing brought to the surface here.

What makes the Glen site particularly striking is not any single feature but its context within the landscape. The field sits on the flat bottom of a drained peat basin, a low-lying, once-waterlogged setting that would have been well suited to the water-dependent activity associated with fulachtaí fia. And this was no isolated episode of prehistoric use: two further fulachtaí fia lie within fifty metres, one roughly 28.5 metres to the west-south-west and another approximately 46 metres to the south-west. The cluster suggests repeated or sustained activity in this corner of the basin over time, perhaps drawing on the same reliable water source. The tillage ridges that had mantled the field for generations, concealing these remains, were only removed in the late twentieth century, meaning the archaeology here had been quietly preserved beneath the cultivated soil long after the wider landscape had been transformed.