It is easy to miss, and that, in a sense, was always the point. The feature is believed to be a ha-ha, a sunken boundary wall or ditch designed to keep livestock away from a country house's formal grounds without interrupting the view from its windows. The genius of the ha-ha was its invisibility: from inside the house, the lawn appeared to flow seamlessly into the wider landscape, while a hidden vertical drop on the far side made the boundary impassable to animals. It was a fashionable conceit among eighteenth and nineteenth-century Irish and British landed estates, combining practical function with the period's taste for managed, apparently natural scenery.

The feature survives, if tentatively, on the 1908 edition of the Ordnance Survey six-inch map, where an irregular line of hachures, the cartographic shorthand for changes in ground level and slope, traces what may be the earthwork's course. That it appears on this edition alone, without corroboration from earlier or later mapping, gives the identification a degree of uncertainty; the word "possible" follows the feature throughout its recorded history. What does seem clear is that the slightly raised ground corresponds in position and character to what one would expect of a ha-ha placed to define the ornamental grounds immediately before the house. The undulating terrain of this part of Laois would have made such a device both practical and visually effective.