Along the northern side of the Shournagh River valley in mid Cork, a sequence of these early medieval enclosures sits at measured intervals, suggesting a deliberate, organised presence in the landscape rather than the opportunistic scatter more commonly found. The Coolmona example is one of that group, a circular earthwork just over thirty-four metres in diameter, its interior now thick with coniferous trees that have made the old enclosure their own.

A ringfort, sometimes called a rath, is a roughly circular area enclosed by one or more earthen banks and ditches, used in early medieval Ireland primarily as a farmstead. The Coolmona fort preserves its main bank to an internal height of about 1.6 metres, though it is heavily overgrown with vegetation. Writing in 1939, a researcher named Hartnett noted the remains of a second bank on the eastern side, making this a bivallate example, at least in part, which typically signals a settlement of some local importance. That outer bank has since degraded considerably. The grouping of five such enclosures along the same valley side is the more striking detail. Such alignments are thought to reflect organised landholding or familial territories in the early medieval period, when ringforts were at their most active as lived-in places, roughly between the fifth and twelfth centuries.