The video below, by Sean Charlton White, shows Raphael Bacot, from Lausanne, on one of his attempts to cross between the 2,331 m Tour d’Ai, and 2,326 m Tour de Mayen, on a slackline.
Amazingly, he manages to stay on his feet despite the strong wind. The polyester line was suspended across the 325m gap between the two peaks, in the Vaud Alpes near Leysin, in Switzerland. Lake Geneva can be seen in the background.
According to the website Swiss-slackline.ch Raphael Bacot managed, after some failed attempts, to walk the full length of the 325m line in both directions.