Just west of Paris, Hauts-de-Seine is France’s wealthiest department, mixing corporate towers of La Défense with leafy suburbs like Neuilly-sur-Seine and Boulogne-Billancourt. The Seine riverside, Bois de Boulogne, and grand mansions provide a high-end urban lifestyle. Property commands premium prices—luxury apartments, 1930s villas, and sleek penthouses dominate this business and diplomatic hub.