Windsor Castle, built in the 11th century by William the Conqueror, is the oldest and largest occupied castle in the world and a favourite residence of the royal family. Tour the State Apartments and Semi-State Rooms, spot works of art by Rembrandt and Leonardo da Vinci, visit the imposing Gothic St George’s Chapel, the final resting place for British monarchs including Edward IV and Queen Elizabeth II, and witness the rousing Changing of the Guard ceremony.