Paris, France

Baron Haussmann's 19th-century remodelling gave Paris its defining aesthetic—wide boulevards, uniform cornice heights, cream limestone facades—creating 1,400km of streets lined with 6-story buildings. It absorbs radical modern interventions like the Pompidou Centre, Louvre Pyramid, and Grande Arche de la Defense, outpacing #7 Amsterdam's balance of old and new by preserving 90% of its historic core.