The rath at Knockaderry in County Kerry went considerably further. It was built with three concentric rings of earthworks, a configuration known as a trivallate rath, and that degree of elaboration is relatively uncommon. Whether this reflected genuine social prestige, a need for heightened security, or simply the ambitions of a particular family, it set the site apart from the majority of its contemporaries.

Ringforts, also called raths, were the typical enclosed farmsteads of early medieval Ireland, broadly spanning the period from around the fifth to the twelfth century. They were built by raising banks of earth, sometimes faced with stone, around a circular interior used for habitation and the sheltering of livestock. At Knockaderry, the enclosure measured approximately thirty metres in diameter, a figure recorded on Ordnance Survey maps as far back as 1846 and confirmed again on the 1897 revision. The triple line of defences consisted of an inner earthen bank, a fosse (a cut ditch), a middle bank, a second fosse, and an outer bank beyond that. These elements survive most clearly along the western arc of the monument, where the middle bank still stands to an external height of 2.6 metres, the most imposing of the three. The site now sits in level pasture, its earthworks heavily overgrown and truncated, and the interior is no longer accessible.

What remains is fragmentary but legible if you know what you are looking at. The western side of the enclosure preserves enough of the original profile to convey something of the original scale, with the staggered ridges and hollows of bank, ditch, bank, ditch, and bank still readable in sequence across a relatively short span of ground.