Three-dimensionality can be seen as architectures fundamental existence, the professions acclaimed domain. In times of globalism and scale enlargement, an update of this definition seems needed: metres turn into kilometres, “M3” becomes “KM3”. KM3 is a story about a world that is getting dense. Very dense. It constructs its logical response: a city that is denser. A city that is continuously under construction, with space for limitless capacities, populations. Beyond scarcity. Beyond separation. Beyond pessimism and protectionism. The 3D City. A free-fall in endless space. From right to left, from front to back, from above to below. Pure depth. KM3 is more a construct than an analysis. KM3 is a hypothesis, a theoretical city, a possible urban theory. KM3 can also be seen as a science-fiction novel, a twin pair that describes this upcoming city as an emerging presence, an already existing other world. The book includes a DVD of animations and two urban planning software programs by MVRDV. Biography: MVRDV was set up in Rotterdam (the Netherlands) in 1991 by Winy Maas, Jacob van Rijs and Nathalie de Vries. MVRDV produces designs and studies in the fields of architecture, urbanism and landscape design. Early projects such as the Light Urbanism study for the Municipality of Rotterdam, the headquarters for the Public Broadcasting Company VPRO and housing for elderly WoZoCos in Amsterdam brought MVRDV to the attention of a wide field of clients and gave them international acclaim. The office continues to pursue its fascination and methodical research on density. It uses a method of shaping space through complex amounts of data that accompany contemporary building and design processes. The office first published a cross section of these study results in FARMAX (1998), followed by a.o. MetaCity/Datatown (1999), Costa Iberica (2000), Regionmaker (2002) and 5 Minutes City (2003). The products of this approach vary and range from buildings of all types and sizes, to urban designs to publications and installations. Realized projects include the Dutch Pavilion for the World EXPO 2000 in Hannover, an innovative business park Flight Forum in Eindhoven, the Silodam Housing complex in Amsterdam, the Matsudai Cultural Centre in Japan, two Houses at Borneo Sporenbrug in Amsterdam, offices in Unterf?rung Munich, the Lloyd hotel in Amsterdam, an urban plan and housing in Ypenburg and the futuristic installation Metacity/Datatown that is travelling around the world.