Somewhere in County Waterford, a thatched house and a cluster of cabins were recorded in the mid-seventeenth century and then, in a sense, vanished. They appear in the Down Survey terrier of 1655 to 1656, a vast Cromwellian-era mapping and land documentation project commissioned to catalogue Irish landholdings following the upheavals of the 1640s, and they have never been conclusively located since.

The Down Survey, directed by William Petty, was among the most ambitious administrative exercises carried out in early modern Ireland, producing detailed written terriers, that is, descriptive registers of land parcels, alongside its famous maps. The Castlereagh entry records a thatched house and some cabins, modest structures that would have been entirely typical of rural settlement in this period, when even relatively substantial households were often roofed in thatch and accompanied by small outbuildings for labourers or livestock. What makes the Castlereagh reference quietly puzzling is that these buildings remain unidentified on the ground. The most plausible candidate for their location is the nearby castle site, suggesting the domestic structures may have clustered around or within an older fortified enclosure, a common enough arrangement in post-medieval Ireland where earlier stonework offered both shelter and a degree of status.