An obdurate and brooding Norman mass looming over the River Shannon, Limerick's showpiece castle, with its vast curtain walls and towers, was built on the orders of King John of England between 1200 and 1212. The massive twin gate towers still stand to their full height. A multimedia experience that provides an excellent potted history of Ireland in general, and Limerick in particular, is followed by exposed archaeology in the undercroft and a tour of the courtyard and fortifications.

　　Upstairs from the cafe, don't miss the exhibitions on the castle's archaeology and the development of Georgian Limerick, or the view from the top of the gate towers, though the best views of the castle itself are from the riverside walk on the far side of the Shannon. Book online for discounts.