This is a fulacht fia, a type of prehistoric cooking or processing site found in great numbers across Ireland, typically consisting of a horseshoe-shaped mound of fire-cracked stone beside a water source and a trough. The form here is consistent with that pattern: the mound measures roughly eight metres along its longer axis, and the hollow at its centre opens to the south-east, directly facing the spring that would once have supplied the water essential to how the site functioned.

Fulachtaí fia are most commonly dated to the Bronze Age, though some examples span a wider range of periods, and their exact purpose has been debated, with cooking, textile processing, and bathing all proposed. The terrace at Knockanes is notable for concentrating more than one such site: a second fulacht fia lies approximately fifty metres to the south-west on the same karstic platform, and Tom Coffey recorded a cluster of these monuments in the area in 1994. The geology matters here. The Burren's carboniferous limestone creates a distinctive landscape of flat terraces, grikes, and reliable springs, and it is beside one of these natural water sources that the monuments were placed. Both sites were formally listed in the Record of Monuments and Places in 1996.

The mound today is largely swallowed by long grass, ferns, and blackthorn scrub, which makes it genuinely difficult to read in the field. Visitors standing on the terrace would be looking for a subtle rise in the ground rather than any dramatic earthwork, and the vegetation gives little away. The Burren National Park setting means the wider landscape is itself part of the context: this was an ancient working place tucked into a karst shelf, close to water, far enough from anywhere obvious that it has survived largely undisturbed, if largely unseen.