New York City is a metropolis in a constant state of metamorphosis. The redevelopment of the existing cityscape plays a fundamental role in the future organization of the Big Apple. The guide retraces the history of the architecture that has made the image of New York famous since the 20th century, and analyses the contemporary response, which plays a key role in keeping it as such. The encounter between the 20th century and the world of today is exemplified by the need to update the architecture of the great masters, from a formal, structural and performance point of view. Thanks to the forward looking plans of development and environmental reconversion, even unused infrastructures and post-industrial buildings are protagonists today. In contrast to the ever-increasing number of skyscrapers built, there is room for research into new low-cost housing models. In the same way, the suburbs offer an increasingly popular alternative to the vertical city.