The one at Aghaleague in County Mayo is a rath, the term used for an earthen ringfort, typically a circular enclosure defined by one or more banks and ditches. During the early medieval period, roughly between the fifth and twelfth centuries, these structures served as farmsteads for free farming families, the banks providing a degree of protection for livestock and household against wolves and opportunistic raiders rather than functioning as military fortifications in any serious sense.

Aghaleague sits in a part of Mayo that, like much of Connacht, carries deep layers of settlement history beneath its quiet exterior. The townland name itself is anglicised from the Irish, and the presence of a rath here suggests continuous agricultural use of this land going back well over a thousand years. Raths in this region were often sited with practical logic, on well-drained ground with good views across surrounding terrain, and the earthworks, even when heavily worn by centuries of farming, can still read clearly in the right light, particularly in low winter sun or after a frost when the differential in vegetation marks out the old banks with surprising clarity.