Le Louvre, Paris, France

The Louvre was a medieval fortress and the palace of the kings of France before becoming a museum two centuries ago. The addition of I. M. Pei’s pyramid shocked many when it was unveiled in 1989 as the new main entrance, yet it somehow works, integrating the palace’s disparate elements. The museum’s collections, which range from antiquity to the first half of the 19th century, are among the most important in the world. A good place to start is the Sully Wing, at the foundations of Philippe-Auguste’s medieval keep—it’s in the heart of the Louvre, kids love it, and it leads straight to the Egyptian rooms.
Main attractions: “Venus de Milo,” “Winged Victory of Samothrace,” and Leonardo da Vinci’s “Mona Lisa.”