Translated as Friaochs carn, it was the inaugeration site of the O'Connor clan in Connaught.
It is a small mound about one and a half meters high that sinks slightly at the top and is covered on one side by a dressing of stone. Up until the mid-nineteenth century a proclamation stone stood nearby that featured two sunken footprints, the stone now resides at Clonalis House near Castlerea.
Regarding the inaugeration stone archaeology.ie has this to say
When a portion was broken off the inauguration stone of the O'Conor kings at Carnfree (RO028-69001-) it was moved to the avenue of Cargin House near Tulsk c. 1840 by Daniel Kelly to prevent further damage by quarrying at the original site (Jones 1922-3). It has since been moved to the grounds of Clonalis House in the 1970s, although its authenticity is doubtful (FitzPatrick 2004, 113-5). Roughly rectangular limestone block (dims. of base 0.8m x 0.4m; H 0.45-0.55m) with a subrectangular upper surface (dims. 0.9m x 0.35-0.6m) which has an oval hollow (dims. 0.3 x 0.1m; D 0.7m) divided in two by a ridge at the base to represent a footprint.
On a slight rise of the broad WNW-ESE ridge of Carnfree. It has been re-identified as Carn Lamha (FitzPatrick 2004, 65). Circular, conical and grass-covered mound (diam. of base 16m.3m N-S; H 3.5m) surrounded by a slight berm (Wth 1-1.2m) and fosse (Wth of top 5.5-9m; D 0.3m) (max. ext. diam. 35m N-S). There are also slight traces of an outer bank S-W, but this may be a field bank. The barrow is contained within a triangular area defined by field banks of the field system (RO028-056----). Ditch-barrows (RO028-071----; RO028-072001-; RO028-073----) are c. 60m to the W, c. 60m th the SSW and c. 90m SE respectively. (Herity 1983, 126-7; Waddell 1988, 15-6)
At the crest of the N-facing slope of a WNW-ESE ridge, c. 250m N of the broad WNW-ESE ridge of Carnfree. A limestone slab (L 3.7m; Wth 0.35-1m; T c. 0.25-0.45m) is lying prone and broken in two, 40m E of the ring-barrow