These circular earthwork enclosures, known in Irish as raths, were the standard unit of rural settlement in early medieval Ireland, roughly from the fifth to the twelfth centuries. A typical rath consisted of one or more banks of earth and ditches enclosing a central living area, home to a farming family and their livestock. Thousands survive across Ireland in various states of preservation, and Doonogan's example is one of Clare's less-documented specimens.

The townland name itself carries some weight. Doonogan derives from the Irish, most likely containing the element "dún", meaning a fort or fortified place, which suggests the presence of an enclosure or defensive site was noted in local memory long before any formal record was made. Clare is particularly dense with ringfort remains, a reflection of the county's relatively undisturbed agricultural land and its position within a region that was heavily settled during the early Christian period. Whether the Doonogan rath was a single-family enclosure or something more substantial is not currently documented in publicly available sources.