The fear of heights is one of the most common phobias, but not for Nik Wallenda. On Sunday, Nov. 2 Wallenda completed a back-t0-back tightrope walk over the city of Chicago.

The record breaking daredevil completed a tightrope walk between two skyscrapers 600 feet above downtown Chicago.

The challenge consisted of two parts, beginning from Marina City’s West tower, approximately 534 feet high. He crossed above the Chicago River to the Leo Burnett building, finishing 635 feet in the air. After, Wallenda walked back to the West tower put on a blindfold and walked to the East tower. Wallenda did not wear a harness during his record breaking stunt.

“If (the wind) gets bad enough I go down to the safety vat wire and I’ll grab onto that wire and wrap around and wait for help,” Wallenda said in an interview.

Thousands of cheering fans gathered around the towers on the cold Sunday night to watch the 35-year old complete the back-to-back walks.

Wallenda said he next wants to recreate a 1,200 foot-long high wire in Tallulah Falls Gorge in Georgia, made famous by his great-grandfather who fell to his death in a tight rope stunt in Puerto Rico at the age of 73. The famous walk includes two headstands on the high wire.

Wallenda wants to use actual vintage footage of Karl Wallenda’s walk to create the illusion of them sharing the high wire.

“My dream is to actually walk the wire with my great-grandfather. I get chills even thinking of it” said Wallenda.