Windsor Castle is a royal residence located in Windsor, Berkshire, England, about 25 miles west of central London. Built originally in the 11th century by William the Conqueror after the Norman invasion, it is the oldest and largest occupied castle in the world. Over its nearly 1,000-year history, Windsor Castle has served as a royal home and fortress and remains an official residence of the British monarch today. The castle combines features of a fortress, palace, and small town, covering about 13 acres. It has been the home to 40 monarchs and includes notable features such as the lavish State Apartments, St George's Chapel (where Queen Elizabeth II was laid to rest), and Queen Mary’s Dolls’ House. The structure has undergone numerous phases of building and restoration, reflecting architectural styles from medieval through Georgian and Victorian periods. It is a popular tourist attraction and continues to be used for official state visits and royal events.