The remaining stonework, with parts of the southwest and northeast walls still visible, traces out a rectangular footprint measuring approximately 14 metres from southeast to northwest and 12 metres from southwest to northeast. Whilst the ruins themselves offer few clues about their original purpose, the building’s orientation and dimensions suggest a defensive structure rather than an ecclesiastical one, as noted by archaeologist O’Flanagan in 1933.

The 1550 Survey of Offaly provides a fascinating glimpse into Monasteroris during the Tudor period, documenting two castles at the site; one described as ‘newlie builded and thother all runyose’. This same survey paints a picture of wider destruction in the area, recording the friary walls as ‘burnyd and rasid’, though a mill and orchard were still functioning at the time. The survey, conducted during the English crown’s efforts to map and control Irish territories, captures a moment of transition when older medieval structures were falling into ruin whilst new fortifications were being erected.

Today, these weathered foundations serve as a tangible link to a turbulent period in Irish history when tower houses dotted the landscape, providing both residence and defence for local lords. The site’s elevated position would have offered strategic advantages, allowing occupants to monitor movement across the surrounding lands whilst the tower house itself provided a secure base during an era marked by political upheaval and territorial disputes.