World Tunnel Congress 2016, 22nd -28th April 2016, A successful week in San Francisco: 2 319 attendees gathered around the latest technological and technical innovations in urban underground planning   Fom April 22nd to 28th in San Francisco, United States, the International Tunnelling and Underground Space Association (ITA) held its 42nd General Assembly along with the 2016 World Tunnel Congress (WTC), co-organised with the Underground Construction Association of SME. As states demonstrate strong needs in tunnels and underground spaces for public transports, interchange subway stations, hydroelectric infrastructures, etc, the WTC 2016 was a unique occasion to discover the latest state-of-the art innovations in urban planning and underground construction projects in the United States and worldwide. This international event, widely recognised among tunnelling professionals, civil engineers, and public authorities, is, indeed, the top attended annual “rendez-vous” that currently permits to have a clear vision of the latest projects of underground infrastructures over the planet.