What survives is a circular enclosure roughly thirty metres across, defined by an earthen bank and, along its northern arc, an outer fosse, or ditch, cut to about 0.7 metres deep. The bank itself rises only around 0.4 metres on the interior, which gives a sense of how much these features can diminish over the centuries under the slow pressure of agriculture and weather.

This is a rath, the Irish term for a ringfort, a type of enclosed farmstead built predominantly during the early medieval period, roughly between the fifth and twelfth centuries. Thousands of them once dotted the Irish countryside, serving as defended homesteads for farming families of some local standing. The earthen bank and external ditch would have provided both a physical boundary and a degree of social statement, marking out a household's territory. At Glenleigh, the northern bank has been absorbed into the existing field fence system, a quiet illustration of how the working landscape has quietly folded ancient boundaries into its own logic. The rest of the perimeter survives as little more than a low rise in the ground, the kind of subtle undulation that reads clearly on a calm winter morning when low light rakes across the grass, but dissolves into the general texture of a field in summer.