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 view of the Sheikh Zayed highway in Dubai and some high rise buildings, November 8, 2007. (Photo by Steve Crisp/Reuters)

In this September 1, 2015 photo, street artists Jenaro de Rosenzweig, left, and Alejandro Revilla pose for a portrait behind a restaurant's window covered with a mural by artist Francisco Munoz, signed with his artist's name below, in the Roma Norte neighborhood of Mexico City. Rosenzweig and Revilla founded the “Street Art Chilango” cooperative in March 2013, which is filling neighborhoods with public art by local street artists. (Photo by Rebecca Blackwell/AP Photo)

Winston Leonard Spencer Churchill (1874–1965), British Statesman and Prime Minister inspecting the boys from a training ship. (Photo by Hulton Archive/Getty Images). 1912

Women take part in Glowork exhibition in Riyadh, Saudi Arabia on September 28, 2017. (Photo by Faisal Al Nasser/Reuters)

India's Central Reserve Police Force personnel take part in a rehearsal for the Republic Day parade on a cold winter morning in New Delhi January 8, 2014. (Photo by Ahmad Masood/Reuters)

Rag pickers collect recyclable material at a garbage dump in New Delhi November 19, 2014. (Photo by Ahmad Masood/Reuters)