The site, a probable barrow, reveals itself through a cropmark, the faint differential in vegetation growth caused by buried ditches and banks beneath the soil, which appears as a circular feature roughly 26 metres in diameter, with an outer bank bringing the overall spread to approximately 48 metres north to south. A field drain bisects it, a mundane intrusion that speaks to how thoroughly the landscape has been reworked around it.

Barrows are prehistoric burial monuments, typically consisting of a raised earthen mound surrounded by a fosse, or ditch, and sometimes an outer enclosing bank. The form visible at Castlewaller, defined by a fosse and a possible outer bank, is consistent with ring barrow types found widely across Ireland, though no excavation record exists to confirm the date or character of whatever lies beneath. The site was identified not through fieldwork but through the close reading of Google Earth orthoimages, a method that has quietly expanded the known archaeological record in recent years, bringing sites like this one to light without a single trowel being lifted. The details were provided by Jean-Charles Caillère and compiled by Caimin O'Brien, with the record uploaded in October 2021.