In the examples provided below, the reader will discover how cities are experimenting with new forms of collaborative and multi-stakeholder governance across different city 'models'. Although the Reflow project tackles the challenge of the transition to Circular Cities, for the scope of this Handbook we have broadened the horizon to other city concepts and visions. As the Circular City is heavily entwined with broader aspects such as digitalization, sharing economy, servitization, urban regeneration and more, we believe that city 'concepts' such as the Smart City, the Sharing City, the City as a Commons, etc. may all offer precious indications and inspiration for collaborative urban governance in the circular economy. Taken further, we might even argue that an effective transition to the Circular City will require these concepts to blend and integrate each other, configuring holistic and comprehensive strategies and plans that cross-cut across climate, educational, business development, urban planning, smart city and citizens participation policies.