Paris is a global metropolis that includes the city of Paris, 123 municipalities of the Hauts-de-Seine, Seine-Saint-Denis, and Val-de-Marne departments, as well as seven municipalities of Essonne and Val d'Oise. It is home to the headquarters of the OECD, UNESCO, and the UN for Education, Science, and Culture. La Défense district brings together 27 of the world's top 500 companies and is responsible for 31% of the national GDP. The French capital ranks third in international investment after London and Shanghai.