The document describes an experiment conducted by Emile Hooge to get diverse groups of people to envision the future of cities by building Lego prototypes. The experiment involved gathering a group, introducing a new visual language using Lego, having participants build prototypes of social innovations for cities, combining the prototypes into a future city model, and then sharing insights. Some conclusions were that the method contributed to dealing with preconceptions, envisioning a desirable future, taking a systems approach, and focusing on values through hands-on prototyping. However, the method has biases of focusing on innovation and feelings over facts, and challenges of maintaining momentum and replicating at large scale.