Windsor Castle, the oldest and largest occupied castle in the world, is a must-visit for history buffs and royal enthusiasts alike. Founded by William the Conqueror in the 11th century, this iconic landmark has been home to 40 monarchs over the years. Visitors can explore the State Apartments, marvel at Queen Mary's Dolls' House, and witness the Changing of the Guard. With its rich history and stunning architecture, Windsor Castle offers a glimpse into centuries of royal life and tradition.