It is, in fact, the remains of a fulacht fia, a type of prehistoric cooking site found in considerable numbers across Ireland, typically dating from the Bronze Age. The defining feature of such sites is the mound itself, built up over time from the discarded by-products of a particular process: stones heated in fire and then dropped into a water-filled trough to bring it to the boil, cracking and shattering in the process. Repeated use over years or generations produced a characteristic accumulation of angular, heat-fractured stone in dark, charcoal-rich soil, and that is precisely what survives here.

The mound at Turlough measures roughly 11.6 metres north to south and 8 metres east to west, rising to a modest height of around 0.6 metres at its northern end and slightly less at the south. Between the two arms of the horseshoe, at the northeast, a shallow depression in the ground most likely marks where the trough once sat, the functional heart of the site where water was heated and, according to the most widely accepted interpretation, meat was cooked. The mound is sod-covered now, blending into the surrounding pasture, but the boggy, level ground in which it sits is entirely typical of such sites, which were almost always positioned near a reliable water source. A ridge to the south overlooks the field, and an east-west road runs along its southern edge. An old field drain clips the southwestern corner of the mound, a small modern intrusion on something considerably older.