The first castle was not built until the 13th century even thought the castle grounds were granted to the Butler family in 1192, so the lands went without a prominent structure for almost two centuries. The residents admitted defeat to Cromwell in 1650 without resistance, because the memories were still unsullied of the ghastly beating the place had suffered in 1599 at the hands of the Earl of Essex and his meager two cannons.

The castle sits on a rocky island in the Suir River, and consists of three distinct sections, surrounded by a thick fortifying wall, with the main structural towers and hails around the innermost section.