What makes it unusual is not its appearance but the documentary thread that connects it to a specific transaction in 1609, when the English crown parcelled out the manor of Disert to a Westmeath landowner and thought it worth recording, among grander assets, a fish pond.

In that year, Sir Robert Nugent of Walshestown received the manor of Dysart under a patent granted during the reign of James I. The grant listed the property's assets in considerable detail: a castle, a hall, a stone bawn (an enclosing defensive courtyard, typically of mortared stone, commonly attached to tower houses of the period), a lough, a stable, two barns, a haggard, forty messuages, fifty gardens, and a fish pond. Fish ponds of this kind were practical features of manorial estates, used to maintain a reliable supply of fresh fish, often for household consumption or for observing the Catholic calendar's many fast days. The pond to the west of Dysart House is a candidate for that same feature, though the identification remains tentative rather than confirmed.