Book excerpt: Redefining Smart & Sustainable Cities, although has been conceived much earlier and has been continually refined over and over, the recent announcement of 100 Smart Cities by the Hon'ble Prime Minister of India, Mr Narendra Modi, and the spate of events thereafter, has made the release of the book rather accelerated. It unfolds for its readers the thus-far little-known story about smart cities that have existed since centuries and what the existing cities can learn from them. The author has taken interesting habitat traits and important data points right from prehistoric times to the modern day. Parallels have been drawn from various parts of the globe cutting across time - right from the Stone Age to the modern Digital Age. The authors have critically analyzed and shown that since the problems had the same set of root causes the solutions can also lie among some of the thriving and sustainable modern-day smart cities of the world. In fact, through careful extrapolation of habitat aspects the author has shown that many of the sustainable smart cities today have undergone similar deterioration for at least some time before these cities were restored and made truly smart. Each chapter weaves into it text and explanations written in a direct and simple manner and is interspersed with interesting pictures, drawings, infographics, and facts and figures directly relevant to the topic under discussion. This makes the book a very engaging and interesting read.