It is made almost entirely of burnt material, the accumulated residue of a fulacht fia, an ancient cooking site typically dating to the Bronze Age. The usual interpretation is that stones were heated in a fire, dropped into a water-filled trough to bring it to the boil, and then used to cook meat, often wrapped in straw or hide. Over repeated use, the cracked and heat-shattered stones were raked out and piled to the side, forming exactly the kind of horseshoe-shaped or irregular mound that now survives here.

What makes the Corbally site quietly interesting is not any single feature but its pairing. A second fulacht fia lies roughly sixty metres to the west, the two sites sitting close enough together to raise questions about how they were used, whether simultaneously or across different periods, and by whom. Fulachtaí fia are among the most common prehistoric monument types in Ireland, particularly in Munster, and their clustering is well documented elsewhere, though the reasons remain debated. Some researchers have suggested communal gatherings, seasonal use, or even industrial processes beyond simple cooking, such as hide-working or brewing. The north bank of a stream would have been a practical choice in any case, given that a ready water supply was essential to the whole process.