Circular enclosures of this kind are a common enough sight in the Irish archaeological record, often the remains of a ringfort, a type of enclosed farmstead built and occupied broadly between the early medieval period and the twelfth century, defined by an earthen bank or banks enclosing a domestic space. Thousands survive across the country in varying states of preservation, some dramatic, some barely legible in the landscape.

By the time anyone went to look more closely at the Glasnamullen feature, in 1989, the site sat within a mature plantation. Conifer forestry, which expanded rapidly across Irish uplands throughout the twentieth century, has a complicated relationship with buried archaeology: it can protect earthworks from the plough while simultaneously obscuring them, compressing them under root systems, and making surface survey difficult. On this occasion, inspection found nothing of archaeological significance still visible above ground. Whether the enclosure had been disturbed before the trees arrived, or whether it simply does not survive in any meaningful form, is not recorded.