National Geographic – Ciudad Nezahualcóyotl is the ur-informal settlement of metropolitan Mexico City. From its beginnings as an illegally developed, planned, and built settlement in the late forties, Neza has served as a powerful image of self-built, so called “informal” urbanism.
http://voices.nationalgeographic.com/2015/03/26/scenes-from-neza-mexico-citys-self-made-city/