Hardest route climbed

The hardest sport climb in the world is "Silence", which has a grade of 5.15d. The 45-meter-long climb is located in the Hanshelleren Cave, near Flatanger, Norway. No other climbs of this grade yet exist. Silence has only been climbed by one person: Adam Ondra (Czech Republic), on 3 September 2017.

"Silence" is a sport climb, meaning bolts have been pre-drilled into the rock, to let the climber focus as fully as possible on the difficulty of the climb.

Ondra initially surveyed and bolted the route in 2013, but quickly realized it would take many years of planning and practice to complete. He built replicas on the hardest sections in his home climbing gym, and spend a total of 50 days over two summers practicing the in Norway.

Almost the entire route is inverted, running across the ceiling of the cave. It is divided into three main sections – an extremely tough initial climb of 15 metres, which ends in an inverted knee-bar rest; then a long section of incredibly difficult bouldering problems (referred to as "cruxes"), followed by a bat-hang rest; and then another set of bouldering problems that lead to the end of the route at the cave mouth.

Climbing grades are largely subjective, relying first on the initial judgement of the climber, and then the assessments of subsequent climbers. As yet, no-one else has completed "Silence", so the grade is based on Ondra's judgement. He decided that it was worthy of a whole new grade because, despite his extensive experience climbing what were previously the world's hardest routes (5.15c climbs) he was initially unable to complete even short sections of the climb without falling. Ondra and his team had to create a whole new training and practice regimen before he could make any progress.

Another route, "Bibliographie" in Céüse, France, was initially graded as a 5.15d (with some uncertainty) by its first ascentionist, Alex Megos in August 2020. The following year, the climb was repeated by Stefano Ghisolfi, and the two climbers agreed to downgrade it to a 5.15c.