Under the banner of “Rethinking Cities: Framing the Future”, the 6th Urban Research and Knowledge Symposium (URKS6) took place in Barcelona from 8-10 October. Professors Ricky Burdett and Saskia Sassen contributed to a plenary discussion on the role of cities and urban development in addressing the needs and aspirations of the bottom billion, and identified promising practices and initiatives that cities can undertake to achieve spatial, economic, and social inclusion. LSE Cities Researcher Dr Antoine Paccoud also presented research from last year’s Urban Age conferences emphasising the influence of the built environment on metropolitan health outcomes. The three-day Symposium, organized by The World Bank in partnership with the City of Barcelona, seeks to contribute and inform policy choices that can help policymakers manage potential economic efficiency, environmental sustainability and social equity tradeoffs associated with urbanisation. The event was webcast live, and presentations and proceedings will be made available at www.rethinkingcities.org.