AFTES, the French Tunnel and Underground Space Association, is holding its 18th Congress on 12-14 October 2026 at the Grand Palais in Lille. This event, held every three years, is a must for underground specialists, and brings together project managers, engineers, architects, town planners, contractors and suppliers, safety and insurance professionals, among others.

The main theme of this year's event will highlight the extent to which the underground environment can provide an appropriate response to the many challenges of our time: “New challenges, underground solutions”.

Aside from the traditional uses for services such as low-carbon public transport or the transport and storage of drinking water and wastewater, underground structures open up a vast array of new solutions to address the challenges facing our societies.

The underground can provide solutions to a number of issues, including the safe transport and storage of energy and final waste, the security and durability of sensitive and strategic installations, the pooling of uses for “maximum utility” projects, an essential condition in a context that demands sobriety and sustainability for future infrastructures.

Underground space also has the potential to be a “tool for urban reclamation”, serving the more sustainable functioning of cities, resources and flows, and the reclamation of surface space for housing, gardens and the like.

This broad theme will focus on sustainable solutions to environmental, energy and safety issues, technological innovations and new techniques in underground works, the underground city and its applications in urban management, the health and safety of workers in underground environments, the financial and organisational challenges of major underground projects and the future of underground infrastructures.

As in previous years, there will be a large number of presentations over the three days, and a large exhibition will provide an opportunity for specialists to present their work and meet one another. The AFTES attaches great importance to the cordiality, friendship and welcoming nature of the numerous attendees, including many international guests and students, which further enhances the quality of the discussions.

A training day on water and underground works will precede the opening of the congress on Sunday 11 October 2026.

Dedicated student days, a special issue of our TES magazine, a photo competition and other events will round off the conference programme.

We hope to see as many of you there as in previous years, and we look forward to welcoming you to this very hospitable region, which is also to reach using low-carbon forms of transport.