These were purpose-built wetland enclosures, typically dating from the seventeenth to nineteenth centuries, designed to lure and trap wildfowl on a significant scale. Funnel-shaped channels called pipes, screened with netting and curved away from the main water body, allowed a trained dog to work ducks into an ever-narrowing passage until they could be taken by hand or in a net. The whole system depended on the birds' instinct to follow something curious along the water's edge rather than fly off in alarm.

The presence of such a structure within a demesne setting is not entirely surprising. Landed estates across Ireland and Britain maintained decoy ponds as a practical food source and, later, as a fashionable amenity that signalled the careful management of land and water. Castlelohort, situated in Cork, would have been one of a relatively small number of Irish properties to invest in this kind of infrastructure, which required considerable initial outlay and ongoing maintenance. The craft of operating a pipe decoy was specialised enough that skilled decoyers were employed specifically for the purpose, and the knowledge passed between them in ways that left little written record.