The one at Cloonreddan in County Clare is a rath, the term used for an earthwork ringfort, typically consisting of one or more circular banks and ditches that once enclosed a farmstead or high-status residence during the early medieval period, roughly between the fifth and twelfth centuries. At a glance, a rath can look like little more than a raised grassy ring, but these were the principal unit of rural settlement for centuries, home to farmers, their families, and their livestock.

Cloonreddan itself is a townland name derived from Irish, and Clare as a county is particularly dense with early medieval remains, its landscape shaped by the same social structures that produced ringforts across the island. A rath of this kind would originally have been a working agricultural enclosure, its earthen bank topped perhaps with a timber palisade, the interior holding a house, outbuildings, and storage pits. In folklore, such sites became associated with the otherworld and the fairy folk, a reputation that helped preserve many of them when surrounding land was cleared or ploughed. Farmers were often reluctant to disturb a rath, and that superstition has kept a remarkable number intact into the present day.