The castle met its end during the tumultuous events of 1641, when it was besieged and destroyed during the Irish Rebellion. Historical records from FitzGerald’s research between 1896 and 1899 document this violent episode, providing a glimpse into the castle’s final days as a functioning fortress.

Archaeological investigations have revealed intriguing evidence of the castle’s former grandeur. To the north of the present graveyard, extensive foundations of buildings have been discovered, along with ancient thick walls featuring arched openings. These substantial remains suggest a structure of considerable size and importance. Whilst the Ordnance Survey 6-inch map places a monastery within the graveyard boundaries, the proximity of these foundations raises interesting questions about their true origin; they may well belong to the castle rather than any religious buildings.

The site continues to intrigue historians and archaeologists alike, with FitzGerald’s early 20th century observations (1903-1905) helping piece together the layout of this lost stronghold. The combination of documentary evidence and physical remains creates a fascinating puzzle, where castle and monastery histories intertwine in the landscape of medieval Kildare. Research compiled by Gearóid Conroy has helped preserve these findings for future generations studying Ireland’s castellated heritage.