The Castle is Nenagh's oldest building, and its construction in the 13th Century laid the foundation for the development of the town. Theobald FitzWalter, whose successors would become Earls and Dukes of Ormond, built the castle and upon its completion c.1220 it served as the main seat of the Butler family, until 1391. The Castle boasts the finest cylindrical keep in Ireland. Like most keeps, it f
ormed part of the perimiter of the fortress, being incorporated in the curtain walls surrounding five - sided courtyard. The Castle has had extensive renovations from 2009 to completion in June 2013. In 2014 the Castle is open for visitors from April to October. Opening times: Tuesday-Saturday: 10am-1pm, 2pm-4pm (last admission 3.45pm). Free admission and free guided tours are available on request. Entrance to the Castle is located on O'Rahilly Street and can be reached via Banba Square (adjacent Nenagh Arts Centre).
