It measures eighteen metres long, fourteen and a half metres wide, and barely thirty centimetres high, a shallow rise of blackened, fire-cracked stone and charcoal that has been accumulating since the Bronze Age. This is a fulacht fia, a type of site found in extraordinary numbers across Ireland, and one of the most distinctive features of the prehistoric Irish landscape.

A fulacht fia, which translates loosely as a cooking place or roasting pit, typically consists of a horseshoe-shaped or oval mound of burnt and shattered stone built up beside a water source over repeated use. The accepted interpretation is that stones were heated in a fire and then dropped into a water-filled trough, bringing the water rapidly to the boil for cooking meat, though some researchers have proposed additional uses including textile processing or even bathing. The defining signature of the site is the mound itself, the discarded burnt stone that was tossed aside after each use, gradually forming the spread of material still visible today. At Doire An Tóchair, a well lies roughly fifty metres to the east, which fits the pattern closely; proximity to a reliable water source was a practical necessity for the whole process to work. These sites date most commonly to the Bronze Age, roughly 1500 to 500 BC, though examples from other periods are known.