Musée National de l'Histoire de l'Immigration in Paris

You're standing at the Palais de la Porte Dorée, at number 293 on avenue Daumesnil, in Paris's 12th arrondissement. This is where the Bois de Vincennes begins, the big woodland on the edge of the city. Today this grand building is France's national museum of immigration history. But take a good look at it, because it was built for a very different purpose.