Windsor Castle, England

Founded by William the Conqueror in the 1070s, Windsor Castle is the oldest and largest inhabited castle in the world, serving as a royal residence for 40 successive monarchs over 950 years. Its 484 acres of grounds include the magnificent St George's Chapel, which houses the tombs of 10 monarchs including Henry VIII and George VI. Windsor is the weekend home of the British Royal Family and receives over 1.2 million paying visitors annually.