King John's Castle, Limerick (must see)

King John's Castle appears almost the same as when it was built in the 13th century. It is probably the best-preserved Norman castle in Europe. The walls, towers, and ramparts are located on King's Island, surrounded by the waters of the River Shannon.

During the Viking era, the island Inis Sibhtonn (King's Island) served as a stronghold of Viking Sea King Tomair mac Ailchi. The Vikings raided up and down the river, pillaging ecclesiastical settlements, until the 10th century when the Dalcassian Clan and the King of Munster put an end to their shenanigans.

The arrival of the Anglo-Normans to the island in 1172 changed everything. A castle, built on the orders of King John and bearing his name, was completed around 1210. Limerick prospered, untrammeled by rebellious lords, Gaelic kingdoms, and pesky Vikings. A mint was established, making pennies and half-pennies. The city had "...stout walls of hewn marble."

The "stout walls" of King John's Castle were badly damaged in the 1642 Siege of Limerick. Garret Barry, General of the Catholic Confederation, undermined the walls, and the castle surrendered. Between 1642 and 1922, it was besieged five times.

King John's Castle underwent massive redevelopment in 2013. There is a new visitor center with interactive exhibits, computer animations, and a cafe with courtyard and river views.