Diffuse urbanization extending across the Ile-de-France region is by no means a new phenomenon; especially in the deuxième couronne (second “crown”), where urbanized spaces blend with natural or agricultural areas. Three spatial forms arose: villes nouvelles (“new towns”); the fringes of Ile de France; and the areas beyond the borders of this region. Municipalities develop greater autonomy from Paris and urban development is triggered by endogenous dynamics. Neighbourhoods from the 1970s and 80s and small suburban towns are renewed. Natural and agricultural areas have been established. New territorial projects combine urban forms, agricultural areas, and landscape management. Communal and regional planning documents set out restrictions for new urbanization zones, yet there are many contradictory types of public regulation: from strong and Malthusian control to a laissez-faire approach in areas targeted for productive activities.