This is a rath, the Irish term for a ringfort, a type of enclosed farmstead built and occupied predominantly between the early medieval period and around the twelfth century. Tens of thousands of them survive across Ireland in various states of preservation, yet each one represents what was once a working domestic site, a family's home and farm set within a bank of earth. The Coolmagort example is univallate, meaning it has a single enclosing bank rather than the two or three concentric rings found at more elaborate sites, and that bank is now heavily defaced and overgrown.

The enclosure measures roughly 37.7 metres north to south and 36 metres east to west, making it a reasonably substantial example of the type. The earthen bank averages about 1.1 metres high with a basal width of around 1.5 metres, though at its best-preserved point, towards the north-east, it reaches 1.55 metres in height and widens to 2 metres at the base. The interior of the site slopes noticeably downward to the east, and no clear entrance can be identified in what survives of the perimeter. That absence of a discernible entrance is not unusual in heavily degraded raths, where centuries of agricultural activity, soil movement, and vegetation growth can obscure original features almost entirely. The site was documented by A. O'Sullivan and J. Sheehan in their archaeological survey of the Iveragh Peninsula, published by Cork University Press in 1996.