King John’s Castle is a 13th-century castle located on King’s Island in Limerick, Ireland. The River Shannon runs in front of the castle, and with the heavy rains, much of the park surrounding the castle was flooded. The site dates back to 922, when the Vikings lived on the Island. The castle gets its name from King John, who ordered the construction of the castle in 1200. Well preserved, this Norman castle still maintains original walls, towers, and fortifications.