The holder of half a dozen world records will walk across the Grand Canyon on a steel cable with nothing but the Little Colorado River 1,500 feet below on June 23. With no tethers or safety nets, the walk will be the highest tightrope attempt ever for the 34-year-old, at a height taller than the Empire State Building. Last year, Wallenda, a seventh-generation member of the “Flying Wallendas” family of acrobats, became the only person to walk a wire over the brink of Niagara Falls. Photo: Nik Wallenda walks across a tightrope 200 feet above U.S. 41 on January 29, 2013 in Sarasota, Florida. (Photo by Tim Boyles)

A model walks the runway at the Hakaan Spring Summer 2012 fashion show during Paris Fashion Week on October 4, 2011 in Paris, France. (Photo by Nathalie Lagneau/Catwalking/Getty Images)

Miss Alsace, Delphine Wespiser walks along the stage during Miss France 2012 Beauty Pageant on December 3, 2011 in Brest, France. (Photo by Pascal Le Segretain/Getty Images)

A model walks down the runway during the Safilo fashion show at the Mercedes-Benz Fashion Pavilion on January 30, 2012 in Stockholm, Sweden. (Photo by Ian Gavan/Getty Images)

A man walks beside a “Wrinkles Of The City” creation near the Berlin cathedral in Berlin April 19, 2013. (Photo by Fabrizio Bensch/Reuters)

A reveller smiles as she walks in the rain at Worthy Farm in Somerset during the Glastonbury Festival in Britain, June 28, 2015. (Photo by Dylan Martinez/Reuters)

Women in Kimono holding an umbrella walk on a street at Ginza shopping district in Tokyo, Japan, March 31, 2016. (Photo by Yuya Shino/Reuters)

A man carrying a sailfish walks through Hamarweyne district in South Mogadishu on March 25, 2015. (Photo by Carl De Souza/AFP Photo)