King John's Castle is a historic fortress located in Limerick, Ireland. Built in the early 13th century, it was constructed under the orders of King John of England to secure the area and control the River Shannon. The castle features impressive stone walls and towers, showcasing medieval military architecture. Today, King John's Castle serves as a popular tourist attraction, offering visitors insights into its rich history. The site includes interactive exhibits and guided tours, allowing guests to explore the castle's past and its role in the conflicts of the region.