Professional mountaineer Audhild Hogasen (left) and Yuri Rhodenborgh, from Norway and the Netherlands respectively, walked on parallel lines at the Moleson peak near Fribourg, Switzerland on Thursday.
They were taking part in the Highline Extreme event - lasting till tomorrow - which will see 25 of Europe's best slackliners walk on eight different lines 45m to 495m above ground.
The Moleson peak is 2,002m above sea level.
Walking on the slackline helps climbers improve their sense of balance. They are secured with ropes so they do not fall down.