Once the stronghold of the powerful Butler family, the castle retains its impressive keep, tower and much of its original defensive structure. It is one of Ireland's largest and best-preserved castles. It is situated on a rocky island on the River Suir. The castle's attractions include an excellent audio-visual show which informs visitors about the castle. As this site is managed by the OPW, school tour visits are permitted free of charge provided certain conditions are met.