There is a vast amount of information about a city which is invisible to the human eye -- crime levels, transportation patterns, cell phone use and air quality to name just a few. If a city was able to be defined by these characteristics, what form would it take? How could it be mapped? Nadia Amoroso tackles these questions by taking statistical urban data and exploring how they could be transformed into innovative new maps. The "unseen" elements of the city are examined in groundbreaking images throughout the book, which are complemented by interviews with Winy Maas and James Corner, comments by Richard Saul Wurman, and sections by the SENSEable City Lab group and Mark Aubin, co-founder of Google Earth.