But the horseshoe shape is the giveaway. This is a fulacht fia, a type of prehistoric cooking or processing site found in enormous numbers across Ireland, typically consisting of a trough dug near a water source and a surrounding mound of fire-cracked stone, accumulated over repeated use as heated rocks were dropped into water to bring it to the boil. The mound at Gortaclare measures roughly 11.6 metres along its northeast to southwest axis, spans about 4.7 metres in width, and rises to just under a metre in height. It opens to the west, the classic horseshoe form preserved with unusual clarity, and where a livestock track has cut through the edge of the mound, the burnt and fragmented stone that makes up its body is plainly visible.

What makes this particular spot more than a single isolated curiosity is the company it keeps. Three further fulachtaí fia lie within a short distance: two sit around six metres to the north, and a third is roughly thirteen metres to the northeast, on the opposite bank of the small eastward-flowing stream that runs along the northern edge of the site. Clusters of this kind are not unheard of in Irish prehistory, and their meaning is still debated; they may reflect seasonal or repeated gatherings at a convenient water source over long periods of time, or activity by different groups who found the same landscape conditions useful. The stream, the level pastureland, and the ridge rising steeply to the south would have shaped the choices of whoever returned here, possibly across generations. The four monuments together form one of those quietly dense prehistoric landscapes that Ireland produces with some regularity, where the ground holds far more than the surface suggests.