That kind of density is unusual even for fulachtaí fia, which are themselves among the most common yet least-understood monument types in the Irish archaeological record. A fulacht fia is, in essence, a prehistoric cooking site: a trough, usually timber-lined, filled with water and heated by dropping fire-cracked stones into it. The stones shatter with repeated use and are discarded into a mound nearby, forming the characteristic horseshoe-shaped spread of dark, burnt material that survives in the landscape long after everything else has rotted away.

At Caherduggan, the principal site presents as a roughly circular spread of this burnt stone and blackened earth, measuring around twenty metres north to south and thirty-six metres east to west, sitting in tillage ground close to a natural spring. That proximity to water is typical; the whole technology depended on a reliable source nearby. What is less typical is the way the other four sites fan out to the north and north-west at intervals of roughly thirty-eight to ninety metres, as if successive generations returned to the same general area and set up new cooking stations within sight of the old ones. Whether they were used simultaneously or represent activity spread across centuries is not something the surface record can resolve, but the pattern itself suggests this particular corner of north Cork was a place people came back to, repeatedly, over a long stretch of prehistoric time.