The structure, which could be associated with either Ballyengland or Castle Hewson, was documented in 1840 when surveyors noted that the original castle had been surrounded by a defensive wall. This wall's foundation appears to have been repurposed as the base for the south wall of Castle Hewson House, demonstrating how successive generations adapted and built upon earlier fortifications.

The ruins themselves present an impressive sight, standing just north of Castle Hewson House. According to the Ordnance Survey Name Books for Askeaton Parish, the rectangular structure remained remarkably intact in the mid-19th century, with all four walls standing and reaching two storeys in height, topped by an arched roof. At that time, the adjacent Castle Hewson House was occupied by William Hewson, likely a descendant of the family who gave their name to the property.

Bawns were essential features of plantation castles and fortified houses throughout Ireland, serving as walled courtyards that provided protection for livestock, supplies, and residents during raids or sieges. This particular example in Ballyengland Upper represents the kind of defensive architecture that once dotted the Limerick countryside, where English and Anglo-Irish landowners sought to protect their holdings in an often hostile environment. Today, these ruins stand as a tangible link to the complex layers of Irish history, where each generation built upon, adapted, or incorporated the structures of those who came before.