A fulacht fia is a type of Bronze Age burnt mound, found in great numbers across Ireland, and typically formed around a trough into which water was poured and heated by dropping fire-cracked stones. Over time, the discarded burnt stone accumulates into the characteristic horseshoe or crescent shape. At Gurteen, that horseshoe has been pulled apart by the stream running through it, leaving two separate crescents of blackened material on the north bank of a tributary of the Glashagoruv River.

The western mound measures roughly 5.35 metres east to west and 4.4 metres north to south, rising to about 0.6 metres in height. The eastern mound is somewhat smaller in width at 2.2 metres east to west, but taller at around a metre high. Between them, where the original trough and the connecting arc of the mound once sat, the stream has done its slow work of erosion. The site does not stand alone in the landscape: a standing stone lies approximately 60 metres to the east, a reminder that prehistoric communities left multiple kinds of marks across the same ground, though the relationship between the two features is not recorded.