CHAMPS ELYSEES AND INVALIDES.: The river Seine dissects this area, much of which is built on a monumental scale, from the imposing 18th century buildings of les Invalides to the Art Nouveau Avenues surrounding the Effeil Tower Two of Paris's grandest thoroughfares dominate the neighbourhood to the north of the Seine : the Champs Elysées has many smart hotels and shops but today it is more downmarket; and the rue du Faubourg Saint Honoré boasts the heavily guarded Palais de l'Elysée. The village of Chaillot was absorbed into the city in the 19th century, and many of its opulent Second Empire mansions are now ambassies or company headquarters. Streets around the place du Trocadéro and the Néo-Classical Palais de Chaillot are packed full of muséum and elegant cafés.