5. Dublin Castle
Dublin Castle, constructed in the early 13th century on the site of a Viking settlement, served as the administrative and ceremonial center of English, and later British, rule in Ireland for centuries. Following Ireland’s independence in 1922, the castle was handed over to the new Irish government. Today, it functions as a major government complex and a key tourist attraction, hosting state ceremonies and offering insights into Ireland’s colonial past and modern statehood. For more information, visit Dublin Castle.ie.