This book explores a simple but powerful idea. The way we organize the ground of our cities impacts everyday life. In other words, the street systems, plot patterns and building arrangements we lay down on the ground influence, first, the main three-dimensional aspects of building fabrics and then, socioeconomic diversity and environmental sustainability. This scientific evidence is relevant not only to the analysis of past and present settlements, but also to the planning and design of future cities. This idea is explored in the world's first megacity, a place with a singular role in the last two centuries of humankind's urban history and with unique contemporary dynamics - New York. We argue that if the ground plan can make it there, it will make it anywhere.