Tell me what is urban for you and I tell you who you are. As opposed to the colonial era of the 19th century, the term "urban" today no longer indexes a normative cultural concept - such as expressed, for instance, in the "European City" - but represents a cosmos of extremely varied notions determined by geographical, cultural, and individual preferences. If we want to get a grip on what is "urban" today, we have to capture it in all its disguises, gradations, and transformations occurring simultaneously on a global scale.Urban Transformation takes us on a global dérive through a carefully selected series of emerging urban conditions in five continents, seen through the eyes of more than 50 international architects, urban planners, politicians, and artists including Saskia Sassen, Robert Somol, Jean-Philippe Vassal, Eyal Weizman, Teddy Cruz, Keller Easterling, Rahul Mehrotra, Enrique Peñalosa. The book makes a pledge for a differentiated understanding of urban culture at the beginning of the 21st century, embracing cultural idiosyncracy while adhering to a universal ambition: to cultivate the city as the prime arena of human existence, not only because it is the place where since recently the majority of the global population is living, but also because the city is the only type of spatial organization able to accommodate an ever-increasing amount of people on earth in a sustainable way.