The catalog of the 6th edition of the International Architecture Biennale Rotterdam contains a detailed description of the exhibition URBAN BY NATURE– and of all of the projects that are part of it. Dirk Sijmons contributes an introduction to the theme and introduces the different sections of the exhibition. The work process and results of the three IABR–Project Ateliers are highlighted. Other contributions are by Ahmed Aboutaleb, Yves de Boer, George Brugmans, Johan van de Gronden, Maarten Hajer, Eric Hercules, Henk Ovink, Jelle Reumer, Piet Vollaard and Charles Waldheim.