Alex Honnold says he needed to know if scaling the Taipei 101 was even possible before he did Netflix’s "Skyscraper Live" special, so he turned to a more traditional way of climbing to find out.

Alex Honnold just successfully Taipei 101, a 1,667-foot skyscraper, all by himself with no ropes or assists—and it was broadcast live on Netflix.

Honnold’s free solo climb of the iconic building in Taiwan’s capital city was being broadcast live on Netflix with a 10-second delay.