Paris's 7th arrondissement was created at the time of the capital's expansion during the beginning of the 19th century. Home to Paris's well-to-do families, the 7th arrondissement numbers among the capital's beaux quartiers or "beautiful quarters". This arrondissement is also home to numerous French ministries, the Assemblée Nationale and the Hôtel des Invalides, as well as the headquarters of UNESCO and quite a few embassies. This is the capital's most expensive district per square metre. Principal monuments and sites: the Assemblée Nationale, Les Invalides, UNESCO, the Champs de Mars, the Eiffel Tower, the Ecole Militaire ("Military School"), numerous ministries, etc.