It is the ghost of a tree-ring, a formal arrangement of trees planted in a geometric pattern as part of a designed landscape, a practice common among the grander country houses of the nineteenth century, where the grounds were as carefully composed as the architecture itself. The circular form shows up clearly in overhead imagery but left no trace on the Ordnance Survey six-inch map made around 1840. It only appears on the subsequent revision, suggesting it was laid out sometime after that first survey.

The tree-ring sits within the grounds of what was once St. Austin's Abbey, a country house built around 1856 in the French Gothic style, with the pointed arches, decorative stonework, and ecclesiastical flourishes that gave such houses their romantic, quasi-monastic character. A second tree-ring, this one roughly triangular rather than circular and located about sixty metres to the north-east, is also shown on the revised Ordnance Survey map and likewise survives as a cropmark. Together they suggest a carefully considered ornamental landscape laid out around the house in the decades following its construction. St. Austin's Abbey was burnt down around 1921, during the period of widespread destruction that claimed many Irish country houses in the years surrounding the War of Independence. The feature was identified and reported by Ruaidhrí O'Maolagáin.

What remains today is essentially underground, or rather encoded in the differential growth of crops over disturbed or compacted soil where the original planting pits and root structures once altered the ground. The site itself is unremarkable to look at in person, which is part of what makes the cropmark evidence so quietly striking. A landscape designed to be seen and walked through now only reveals itself from the air.