[1] Although the site dates back to 922 when the Vikings lived on the Island, the castle itself was built on the orders of King John of England in 1200.

Domnall Mór Ua Briain burned the settlement to the ground in 1174 in a bid to keep it from the hands of the Anglo-Normans.

The castle was built on the boundary of the River Shannon in order to protect the city from the Gaelic kingdoms to the west and from any rebellion by Norman lords to the east and south.

[5]Luke Gernon, an English-born judge and resident of Limerick, wrote an equally flattering account of the city in 1620: a lofty building of marble; in the high street it is built from one gate to the other in one form, like the colleges in Oxford, so magnificent that at my first entrance it did amaze me".

Barry had no siege artillery so he undermined the walls of King John's Castle by digging away their foundations.

Among the improvements were a brand new visitor centre, interactive exhibitions with computer generated animations, and a cafe with views onto the courtyard and the river.