The hut site at Cahermackirilla is modest enough, its double-faced wall reduced to a single course of stone, its interior measuring roughly seven metres north to south and just under six metres east to west. What makes it quietly interesting is a small sunken passage, just under four metres in total length and less than half a metre deep, that begins inside the structure, passes through a probable entrance gap in the western wall, and then continues a short distance further west before disappearing underground. Three stone lintels remain, two of them still in their original positions, one collapsed into the passage at the gap itself. The passage is narrow enough, and apparently shallow enough, that archaeologists believe it was most likely a drain rather than anything more elaborate, though the presence of roof lintels gives it an unexpectedly finished quality for such a utilitarian feature.

The site sits within a large multiperiod field system, meaning the landscape around it accumulated structures and boundaries across many different periods of occupation. The hut does not stand alone: roughly eighteen metres to the south-south-west there is a house site, an enclosure lies about sixty-six metres to the west-south-west, and a cashel sits less than thirty metres to the north-east. A cashel is a stone-walled ringfort, a type of enclosed farmstead used widely in early medieval Ireland, and its proximity suggests this cluster of features may represent different elements of the same agricultural settlement, each built or modified at different times. The irregular plan of the hut itself, with straight southern and western walls but a curving north-eastern side, hints at pragmatic construction rather than any formal design, the shape following the needs of the moment or the availability of stone.