In 1581, Nicholas Nugent led a rebellion against the Crown from this very spot, a bold move that would cost him dearly. Nugent was no ordinary rebel; he held the prestigious position of Chief Justice of the Common Pleas and had married into the powerful Plunket family. His resistance to the cess, a controversial tax imposed by the English administration, led to his replacement by Robert Dillon and ultimately his downfall. Following his troubles, his wife Ellen Plunket petitioned for the lands to be secured for herself and her children, and in 1584 Queen Elizabeth granted the attainted lands back to the family. The castle remained in various branches of the Nugent family throughout the centuries, with the Earl of Westmeath listed as owner by 1670.

Today, what remains of this once-formidable stronghold is remarkably modest; only the eastern wall survives, standing about 4.5 metres high and incorporated into the ruins of a 19th century outhouse. The medieval wall, built with irregular stones and measuring roughly 12 metres in length, was repurposed as the side wall of this later structure, which belonged to the nearby Lake View Cottage. The combination of dense ivy coverage and the blending of medieval and Victorian masonry makes it challenging to distinguish which portions belong to the original castle. A gap in the wall might mark where a fireplace once warmed the castle’s inhabitants, whilst scarring at the southeastern angle shows where the south wall once joined.

Despite the castle’s poor preservation, several architectural fragments found scattered around the site hint at its former grandeur. A punch-dressed doorway jamb stone with rebated chamfering, discovered in the nearby farmyard, displays the sophisticated stonework typical of castles built between 1550 and 1650. Additional chamfered limestone pieces, including what may have been part of a fireplace surround, have been incorporated into a rockery at Lake View Cottage. These finely carved fragments suggest that Robinstown Castle once boasted impressive carved stone doorways and possibly large fireplaces with moulded limestone surrounds, befitting the status of a Chief Justice who dared to challenge the Crown.