Roughly 20 metres across, it is modest enough to be easily overlooked, and yet it appears on Ordnance Survey maps from both 1837 and 1903, suggesting it was a deliberate and lasting feature rather than an accidental mark on the land.

The feature is thought to be part of a designed landscape associated with Annfield House, a category of improvement that became fashionable among Irish gentry estates from the eighteenth century onwards. Such designed landscapes could incorporate ornamental ponds, woodland walks, eye-catchers, and various geometrically arranged plantings or earthworks intended to shape how the grounds were experienced. This particular circular feature remains unidentified in precise terms, but its regularity and its presence on successive map editions points to intentional construction. Adding a further layer of interest, a possible decoy pond lies roughly 200 metres to the east. A decoy pond was a managed water feature used to trap wildfowl, typically by means of curved, netted channels called pipes that led birds away from open water and into capture. Whether the circular feature and the pond formed part of the same designed scheme is not established, but their proximity suggests they may have belonged to a coherent, if now largely vanished, landscape arrangement around the house.