MAP 22.2 The Modernization of Paris, ca. 1850–1870 The addition of broad boulevards, large parks, and grand train stations transformed Paris. The cutting of the new north-south axis — known as the Boulevard Saint-Michel — was one of Haussmann’s most controversial projects. His plan razed much of Paris’s medieval core and filled the Île de la Cité with massive government buildings. Note the addition of new streets and light rail systems (the basis of the current Parisian subway system, the “metro”) that encircle the city core, emblematic of the public transportation revolution that enhanced living conditions in nineteenth-century European cities.