On a gentle north-west-facing slope in Ballintruer More, County Wicklow, a circular enclosure roughly eighteen metres across has left no trace that a person standing in the field could detect. No mound, no stones, no visible boundary. The site announces itself only in aerial photographs, where differences in soil moisture and crop growth reveal the ghostly outline of a fosse, the ditch that once defined the perimeter of what may be a prehistoric barrow.

A barrow is an earthen burial monument, typically raised over one or more interments, and they appear across Ireland in considerable variety, from large passage tombs to modest ring barrows defined by little more than a shallow ditch and a low bank. The Ballintruer More site falls into the category of cropmark archaeology, a discipline that came into its own during the twentieth century as aerial survey became more systematic. When a buried ditch or bank affects how deeply roots can penetrate, the crops above it grow at a slightly different rate, and under the right conditions of dry weather and low sun, these variations cast faint but readable shadows across a field. The photograph that revealed this particular enclosure was taken as part of the Cambridge University Collection of Aerial Photography, and it remains the only evidence that something deliberately made once occupied this slope. The site lies close to at least one other recorded monument in the same townland, suggesting the area may have held some significance in the prehistoric landscape of east Wicklow.