The daredevil climber is well known for his ascents of impossibly tough routes without using any safety equipment.
For most people, climbing up a mountainside is daunting enough, but for Alex Honnold - a 40-year-old American free solo climber whose incredible ascents have made him a household name - climbing just isn't the same unless it is being done without any ropes, harness or safety equipment whateoever.
In 2017, he became the first person in the world to free solo a full route on El Capitan in Yosemite National Park - an ascent still considered one of the greatest climbing achievements in history.
But it is not only mountainsides and cliff edges that Honnold is adept at climbing - this week he saw the whole world hold its breath as he climbed up the outside of the Taipei 101 building in Taiwain - an ascent of over 500 meters with nothing but thin window ledges to hold on to most of the way up.
Using absolutely no ropes or safety equipment at all, Honnold carefully made his way up the building's smooth exterior while camera crews and an audience of onlookers watched with baited breath.
The entire ascent was also live-streamed on Netflix, necessitating the streaming service to introduce a delay in the feed - enough to end the broadcast abruptly should he slip and fall to his death live on air.
As luck would have it, though, Honnold's incredible skills and calm nerves saw him to the top.
He celebrated the achievement by uttering a single word - "sick".
You can check out a highlight reel of the climb below.