Where exactly does a city start? Where does it end? Often, people cross city borders in their daily lives without realising it. Beyond mobility, the management of essential resources such as energy, food, health, access to water, among many others, require management beyond municipal boundaries. For this reason, there is a political responsibility to rethink traditional divisions, bridging the gap between rural and urban, city and nature, and responding to people’s real needs. If we live on a metropolitan scale, we must think and manage on a metropolitan scale. With more than 35 years of experience, we bring together leaders and representatives from the world’s largest cities and metropolitan areas. Together, we elevate the collective voice of metropolises on the global stage, connecting them with the global agendas, while building our members’ individual capacities to better deliver public policies and services to metropolitan dwellers.