This monograph, the second in a collection featuring artists and the architects who maintain a critical view of the contemporary world, is devoted to the distinguished Hun- garian architect, Yona Friedman, who lives and works in Paris.Yona Friedman’s work spans urban models, theoretical texts and animated films. He has participated in several biennial art ex- hibitions, including Shanghai, Venice and Documenta 11. His visionary, ground-break- ing ideas have been at the forefront for sev- eral generations of architects and urban planners, and have clearly influenced the likes of Kenzo Tange, Arata Isozaki or Ber- nard Tschumi.While Friedman is still active and remains so- cially committed, his most important ideas stem from the fifties and sixties. In 1956, he published his “Manifeste de l’architecture Mobile,” which set an urban structure on piles suitable for areas where building had not been not possible. This text was in turn used as the founding document of the Groupe d’e?tude d’architecture mobile (GEAM). He de- veloped urban concepts such as La ville spa- tiale—the Spatial City where dwellings are freely distributed by the citizens thanks to low-cost, reusable mobile models. In 1965, along with Ionel Schein, Walter Jonas and others, he founded the Groupe International d’Architecture Prospective (GIAP).