The antiquarian Westropp, writing in the early 1900s, noted that the only documentary evidence he could find was a brief mention from 1657 referring to a "Castle on Polagh" in the Down Survey archives. Beyond this single reference, the site's history proved frustratingly elusive, leading Westropp to consider it a doubtful location altogether.

Despite the scarcity of written records, visual evidence from the 17th century offers a tantalising glimpse of what once stood here. The Down Survey map of Coshma Barony, drawn during Cromwell's comprehensive mapping project of Ireland, depicts what appears to be a tower house castle perched on raised ground at Pollagh. These tower houses were the fortified homes of choice for the Irish gentry from the 15th to 17th centuries; compact, defensive structures that combined residential comfort with military practicality.

Today, visitors searching for Pollagh Castle will find little if anything remaining of the structure shown on that old map. Whether it fell victim to Cromwellian destruction, was dismantled for building materials over the centuries, or simply succumbed to time and weather remains unknown. The site serves as a reminder of how many of Ireland's smaller castles have vanished almost without trace, leaving behind only cryptic map markings and the occasional archival note to hint at their former existence.