The average slackline is between one and two inches wide, which is why people are instantly impressed whenever someone breaks one out and can maintain their balance for an extended period of time. It's even more impressive when tricks are thrown into the equation. French professional slackliner Théo Sanson takes slacklining to the extreme, and writes on his website that he'd "rather die from passion than boredness." During a recent visit to Castle Valley, Utah, the daredevil traversed a 500-meter-long slackline (approximately 1640 feet) between two massive geologic formations: Castleton Tower and the Rectory, both of which reach about 400 feet toward the clouds.
The video above was shot by the team at Camp4 Collective and includes drone footage of Sanson's epic stunt. Camp4 Collective writes in the description on Vimeo that this is likely a new world record, though it does not appear to have been verified. World record or not, watching Sanson slowly cross the expanse between the rocks—hundreds of feet above the earth—is enough to make any acrophobic a little queasy.
To learn more about Sanson's accomplishments, check out his website.