Built for the 1937 World's Fair, Palais de Chaillot's sweeping Art Deco curves frame the Eiffel Tower like a stage set. Wander beneath its colonnades, admire carved stonework and gold statues, or simply claim a terrace for people-watching. The twin wings house museums of mankind, maritime history, and architecture, but the real star is the view: arguably the most photographed perspective in Paris, and completely free to enjoy.