Cashels are dry-stone enclosures, roughly circular, built in early medieval Ireland to define a farmstead or settlement, and clocháns are the small corbelled stone huts often found within them. Cathair Fionnúrach is one of a cluster of such structures strung along the lower reaches of Brandon's western face, each occupying a similar position above the flat plain drained by the Feohanagh river, with a clear westward view stretching as far as the Blasket Islands.

The larger of the two huts measures 6.5 metres in diameter, and its entrance is aligned directly with that of the main enclosure, a deliberate arrangement that suggests the two were designed in relation to each other rather than added at different times. A paved pathway once connected the pair of huts; the antiquary T. J. Westropp recorded it, but only three kerbstones remain visible today. The rest of the pathway may still lie intact beneath the thick layer of slurry that has built up inside the enclosure, obscuring what might otherwise be a well-preserved internal arrangement. The site was documented in detail in J. Cuppage's 1986 archaeological survey of the Corca Dhuibhne region, the Dingle Peninsula, which remains the foundational reference for the area's early remains.

The site sits within a landscape unusually dense with early stone architecture, and that density is part of what makes this stretch of Brandon's lower slopes worth attention. The alignment of entrances, the ghost of a paved path, and the question of what else the slurry conceals give Cathair Fionnúrach a quality that bare description somewhat undersells.