Maynooth Castle, National monument and medieval castle in Maynooth, Ireland

Maynooth Castle is a ruined castle at the entrance to the South Campus of Maynooth University in Maynooth, County Kildare. Its surviving gatehouse and Solar Tower are built of rough grey and brownish masonry blocks, with narrow vertical recesses and small square openings high on the walls. A stepped stone base runs along the bottom, and stone steps with a metal handrail lead up to an entrance.

The Fitzgerald family built the castle around 1203 on land granted to them after the Norman invasion of Ireland. In the 16th century, the castle went through a major siege during the Reformation period, after which it was never fully restored.

The castle was the main seat of the Fitzgerald family, one of the most powerful dynasties in medieval Ireland. Today, visitors can see the combined coats of arms of the Fitzgerald and Boyle families carved into the stone walls, marking a change in ownership.

The castle stands right next to Maynooth University and is easy to reach on foot from the town center. Opening hours change by season, so checking ahead before your visit is a good idea.

The 1535 siege lasted ten days before the garrison surrendered; Skeffington's men then executed the defenders at the gate. Silken Thomas and his five uncles were sent to the Tower of London and hanged at Tyburn on 3 February 1537. The gatehouse still carries the combined arms of the Boyles and FitzGeralds, carved after the 1630s marriage alliance.