These cases were selected to showcase innovative and visionary approaches to sustainable infrastructure change across a broad range of contexts, and are intended to demonstrate the abundance of options available that could inspire leaders of other cities to embrace creative solutions. While the approaches may be unique to each case, they can be used to inspire new thinking about infrastructural solutions that leverage existing strengths and resources to address social and environmental needs in an innovative manner. It is important to note that many of these cases have not been fully documented or are based on independently verified information. Nevertheless, they are concrete expressions of widely circulated ideas that have begun to be put in practice, with lessons that loop back into networks that can stimulate the creativity of the next generation of innovators, who could benefit from mastering the tools of material flow analysis.