Considered one of the most eagerly-awaited new automatic metro lines of the Grand Paris Express, line 15 south is scheduled to enter service at the end of 2025. In the meantime, work continues on the site. On Wednesday April 3, 2024, we were able to witness the final welding of rails on line 15 sud in Clamart station, followed by a visit to the future Arcueil-Cachan station. We tell you all about this immersion several meters underground.