The Avenue Foch is an avenue in the 16th arrondissement of Paris, France, named after World War I Marshal Ferdinand Foch in 1929. It was previously known as the Avenue du Bois de Boulogne. It is one of the most prestigious streets in Paris, as well as one of the most expensive addresses in the world, home to many grand city palaces, including ones belonging to the Onassis and Rothschild families. The Rothschilds once owned numbers 19–21.