Watch This Fearless Biker Ride on the Side of a Mountain

You might want to sit down before you watch this video of a daredevil mountain biker essentially defying gravity and riding on a nearly vertical surface of a mountain.

The video, which was captured by drone, shows biker Michal Kollbek taking on the “White Line” in Sedona, Ariz. Kollbek, who was born in Poland and now resides in southern California, shared a short clip on Instagram, where he said this was “one of the scariest things” he’s ever done.

But Kollbek isn’t the first daredevil to take on the White Line. This first person point of view video from 2011 shows just how treacherous the trail is:

(h/t Gizmodo)