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)

Lightning streaks across the sky as lava flows from a volcano in Eyjafjallajokul April 17, 2010. (Photo by Lucas Jackson/Reuters)

Leaves and forest foliage claim abandoned motors at makeshift car graveyards. German photographer Dieter Klein travels the world to find vintage automobiles left to rust in leafy forests and fields. Here: Seemingly camouflaged cars are stacked on top of each other causing them to blend in with the landscape, in 2013, France. (Photo by Dieter Klein/Barcroft Media)

Models smoke during a break at Sevilla de Boda (Seville Wedding) fashion show in the Andalusian capital of Seville November 27, 2015. (Photo by Marcelo del Pozo/Reuters)

Visitors look on as a man (front) inserts two live snakes through his nose and mouth during a performance at an amusement park to celebrate the 65th anniversary of the founding of the People's Republic of China and the 7-day national day holiday, in Jinhua, Zhejiang province October 1, 2014. (Photo by Reuters/Stringer)

A horse- drawn carriage rides along the race course through the Thuringian Forest in Oberhof, Germany, 05 January 2017. Winter found its way to Saxony, Saxony- Anhalt, and Thuringia. In some regions it can get as low as negative 20 degrees overnight. (Photo by Martin Schutt/Zentralbild/DPA)

A dead crocodile is seen on Huangsha Seafood Market in Guangzhou, Guandong Province, China, 22 January 2018. Tsukiji Market of China or Huangsha Seafood Market is biggest one in Southern China and one of the biggest in China, as there are literally hundreds of different varieties of fish and seafood scattered throughout the market. (Photo by Aleksandar Plavevski/EPA/EFE)