Book excerpt: This book explores the concept of livable cities, where people enjoy living and being, and examines indicators of citizens' well-being in relation to the urban environment. It is authored by experts from diverse disciplines, providing a citizen-centered perspective on urban well-being in sustainable, environmentally friendly, and climate-neutral (or -positive) cities. The contributions focus on the human and social aspects of cities, developing operational models and frameworks for circular cities, smart resource utilization, and examining contextual factors such as environmental and neighborhood quality, energy transition, climate neutrality, and recycling as factors that influence the well-being of "homo urbanus.” The chapters approach these topics from various analytical perspectives, including conceptual/theoretical, methodological/modeling, policy/planning, and evidence-based case studies. This book will be of interest to scholars in regional and spatial science, urban geography, economics, and related fields, as well as those interested in urban well-being.