When the Ordnance Survey mapped the area in 1837, the feature appeared on the Fair Plan annotated as a "moat", the word surveyors of the period often used loosely for an earthwork of presumed antiquity. Yet on the more detailed six-inch map produced from the same survey, the same feature was recorded simply as a tree-ring, with no antiquity status attached. That quiet disagreement between two documents from the same year tells you something about how easily a landscape ornament can be read as archaeology, and vice versa.

The feature itself is a roughly oval area, approximately 76 metres north to south and 116 metres east to west, enclosed by a low earthen bank and a shallow external fosse, that is, a ditch running around the outside of the bank. A fosse of this kind is a common element of genuine early medieval enclosures, which is presumably what prompted the "moat" annotation, but the current interpretation is rather more prosaic. The hillock at the centre appears to be a natural rise in the ground that was enclosed and planted with trees to create a deliberate landscape feature, the kind of designed ornament that Georgian and early nineteenth-century estate owners used to give their demesnes a sense of drama and antiquity. Clonhugh House stands about 200 metres to the south, and the tree-ring would have been conceived as part of the same scheme, a visual punctuation mark in the wider designed landscape rather than the remnant of any earlier settlement or fortification.