The site came to light in 2011, a quiet interruption to what would otherwise have been routine land clearance.

Burnt mounds, known in Irish archaeology as fulachtaí fia, are typically the accumulated remains of fire-cracked stone, the debris of a prehistoric cooking or heating process in which rocks were repeatedly heated and plunged into water-filled troughs. Over time, the shattered stone builds up into a low, often crescent-shaped heap. The Dunmahon example sits on the summit of a naturally raised area, close to the townland boundary, a placement that may reflect the way such features were often set near water sources or on marginal ground at the edges of ancient territories. The mound measures roughly nine metres north to south and just under nine metres east to west, rising to about half a metre above the surrounding ground. It is not large by any measure, but its survival into the twenty-first century, even partially, speaks to how quietly these features can persist beneath vegetation and soil when left undisturbed.