This is a rath, the most common type of ringfort in Ireland, typically a circular enclosure defined by an earthen bank and a ditch, known as a fosse, that once served as a defended farmstead during the early medieval period, roughly between the fifth and twelfth centuries. Thousands of these survive across the country in varying conditions, and the one at Cloonacalleen sits towards the more worn end of that spectrum.

The rath measures approximately 27 metres in diameter and retains its defining bank and fosse, though both are poorly preserved. What makes the earthwork slightly more interesting than a simple single-enclosure site is the evidence of a second, outer bank, of which traces survive only at the south-south-east. A double-banked ringfort would originally have implied a degree of additional status or security, making this modest, battered earthwork a little more significant than its current appearance suggests. The numerous gaps and breaches visible in the bank appear to be the result of relatively recent disturbance rather than centuries of gradual erosion, meaning that much of the damage is comparatively new.