The publication aims to identify the trends that shape the future of Barcelona and, in general, the major cities of Europe. The document is a synthesis, fruit of the results of the work sessions and seminars held in 2016 where the situation and the future of the city, challenges and opportunities of today's Barcelona, 25 years after the Olympic Games and with an eye on the next 25 years, 2042. The line of work on the metropolis provides an interdisciplinary approach to the challenges, trends and opportunities of urban regions in the 21st century.