The name, recorded in the Ordnance Survey Field Books as meaning 'little fort of the rock', belonged to a small circular earthwork that appeared on the 1842 six-inch map as a hachured ring roughly 28 metres across, sitting about 150 metres to the north-west of the outcrop known as Carrigcleena. Sometime after that survey was made, quarrying removed it entirely. By 1934, when Bowman documented it, the fort had already been levelled, though its outline, measuring around 35 yards in diameter, could still be traced on land belonging to a R. Barrett. Within that footprint lay a souterrain, an underground stone-lined passage of the kind often found beneath Irish ringforts, used variously for storage, refuge, or both.

The fort itself was a lisheen, the Irish diminutive suggesting a modest single-ramparted enclosure rather than a major defended site. What gives the place a stranger quality is the rock formation it was named for. Berry, writing in 1905, quoted a description of Carrigcleena as 'a wild and romantic spot, a rude elevation, surrounded by a rampart of huge rocks, towering over the country round, and enclosing about two acres of very green ground'. Local tradition held that a passage connected Carrigcleena directly to the fort, effectively linking two natural and man-made formations through an underground route. Whether this referred to the recorded souterrain, to a separate feature, or to folk memory elaborating on the unusual landscape, is not clear. The fort that anchored one end of that story no longer exists above ground, consumed by the same quarrying activity that extracted stone from this part of north Cork.