It is a rath, the Irish term for an earthen ringfort, and though thousands of these early medieval enclosures survive across Ireland, this one carries a particular quality of accumulated time: a stone field boundary has been built directly against its outer southern face, as though successive generations of farmers simply accepted the ancient bank as a convenient wall and worked around it rather than through it.

Ringforts were typically constructed during the early medieval period, roughly between the fifth and twelfth centuries, and served as enclosed farmsteads for single family groups or small communities. They consist of a raised interior platform, a surrounding earthen bank, and in many cases a fosse, which is a ditch dug to provide the material for the bank and to add a further barrier. The Curraghglass example measures just under twenty-five metres across internally and retains both its bank and the remains of its fosse in recognisable form. The original entrance has been lost, which is not unusual; many raths were modified heavily over the centuries as the land around them changed use. A small stone enclosure, probably of modern date, projects from the northern bank into the interior, a modest intrusion that sits awkwardly against the much older earthwork surrounding it.