Built in 1412 by Tuly Odonelan, as proudly proclaimed on its foundation stone (now relocated to the yard of Aughrim National School), this tower began life as a typical Irish fortification of its era. The original structure, measuring 11.5 metres from north to south, would have served as both a defensive stronghold and a symbol of the Odonelan family’s local authority.

The tower’s story took an intriguing turn in the 18th century when it was incorporated into a grander architectural scheme. Rather than demolishing the medieval structure, the estate’s owners chose to reimagine it as the western wing of an adjacent 17th century house, with a matching eastern wing constructed to create a symmetrical Georgian facade. This transformation represents a common practice amongst Irish landowners of the period, who sought to modernise their estates whilst preserving elements of their ancient heritage. Today, whilst the main house has been reduced to foundation level, the tower wing partially survives as a testament to this architectural evolution.

What remains is a haunting four storey western wall, complete with the ghostly outlines of robbed out windows on three floors and a rectangular chimney stack adorned with two string courses; clear evidence of its 18th century refinement. The northern and southern walls survive only as partial returns, though visitors can still make out a doorway in the north wall, its brick insertions suggesting later modifications. Between the ground and first floors, a stone vault remains intact, one of the few internal features to survive the centuries. Though much diminished from its former glory, Ballydonnellan Castle offers a tangible connection to 600 years of Irish history, from medieval clan warfare to Georgian gentrification.