Roughly fifteen by twenty metres across, it is marked by a spread of small, unburnt stones sitting in soil noticeably darkened by charcoal, the residue of fire somewhere in the past. What makes it curious is precisely what it is not: the material is explicitly inconsistent with a fulacht fiadh, the type of prehistoric burnt mound found in enormous numbers across Ireland, typically identified by crescent-shaped mounds of heat-shattered, fire-cracked stone beside a trough or water source. Here, the stones are unburnt, and the pattern does not match that well-documented tradition.

Fulachtaí fiadh, which translates loosely as "cooking places of the deer" though their precise function is still debated, are among the most common field monuments in the Irish landscape, and their archaeology is well enough understood that a site can be reliably distinguished from one. Ballyellis is that distinction in practice: something happened here involving fire and stone, but whatever the activity was, it left a signature that archaeologists have declined to fit into the standard template. The site was recorded in the Archaeological Inventory of County Cork, Volume 4, covering north Cork, published in 2000, and at that point the description offered no further interpretation beyond the observation of inconsistency.