These sites, found in their thousands across the country, typically consist of a mound of fire-cracked stones accumulated beside a trough and a water source, the result of repeated cycles of heating stones in a fire and dropping them into water to bring it rapidly to the boil. What that boiling water was actually used for, whether for cooking meat, bathing, textile processing, or something else entirely, remains a matter of lively archaeological debate.

The Ballinvrinsig site sits close to a spring, which is exactly the kind of water source these monuments required, and overlooks a stream on the slope below. The burnt material visible in the ploughed field represents the accumulated debris of that stone-boiling process, spread and disturbed by centuries of agricultural activity. The site was recorded by Walsh in 1985 and subsequently included in the archaeological inventory of east and south Cork. The combination of spring, stream, and sloping ground is entirely characteristic; fulachtaí fia are almost invariably found near reliable water, often in low-lying or marginal terrain where drainage and access to fresh water converged.