Its origins may reach back to the seventeenth century, making it one of the earlier designed landscapes in the Irish midlands, the kind of place that rarely attracts attention precisely because so little of it remains visible above the surface.

The garden belonged to Clonyn House, the seat of the Nugent family, who held the title Barons of Delvin and later Earls of Westmeath. The Nugents had deep roots at Clonyn; the house itself was probably built on the site of, or incorporated, their earlier medieval castle. By the mid-seventeenth century, the place was already showing its age. The terrier accompanying the Down Survey map of Castletown parish, compiled between 1654 and 1657, described it plainly: 'in Clonyn there is the ruines of a fayre house with a fewe backroomes Wherein the Earle of West Meath dwells with a faire orchard and a garden with a grove of trees.' The Down Survey was a vast mapping project commissioned under the Cromwellian administration to catalogue Irish landholdings, and its accompanying terriers, written descriptive records of each parish, occasionally preserved details like this that the maps themselves left out. Clonyn House does not appear on the survey maps at all, which makes the written description the primary seventeenth-century record of the place.

What survives today at the house itself is a late seventeenth-century five-bay gabled structure, two storeys high, extended at both ends in later periods and now ruinous. A square turret added to the southern side carries a plaque bearing the Nugent family crest. To the east of the house, a rectangular enclosure bounded by a low battlemented wall is thought to be a parterre, a formal garden laid out on two levels. The parterre and the gardens shown 240 metres to the northwest on the 1837 Ordnance Survey six-inch map are likely remnants of the same seventeenth-century scheme, fragments of an designed landscape that was already described as partly ruinous when Cromwell's surveyors came to count the acres.