It encloses a shallow fosse and a few slight hollow depressions whose age nobody has been able to pin down. On the ground it is barely perceptible, and by 2011 it had faded so completely that aerial photography could not pick it out at all. What makes it curious is not what it is, but what it probably was: the ghost of a designed landscape feature, a tree-ring.

Tree-rings were a fashionable element of demesne planting from the eighteenth century onwards, when landowners across Ireland began shaping their grounds according to the principles of designed landscape. A circular or, as here, square earthwork would be thrown up to define and shelter a formal planting of trees, often ornamental, that served as a focal point in the wider grounds. The 1911 edition of the Ordnance Survey six-inch map shows a small cluster of trees at precisely this location, which fits the pattern. The feature does not appear on any earlier edition of the OS maps, and no antiquity was ever marked here, suggesting the earthwork is of post-1700 date and connected with the landscaping of the Edmondstown House demesne rather than with any earlier human activity. The hollow depressions inside the bank remain unexplained, caught somewhere between the ornamental and the ancient.