The giant metal structure sits 330ft above the ground on the roof of a 22 storey office block in Dutch capital Amsterdam on September 6, 2016. Tourists sit in a playground-style chair as they propel themselves them over the edge of the building with only thin-air between them and the ground below. Engineers spent several years designing and building the breathtaking swing. By being fixed to the top of a building it reaches new heights – dwarfing other swings around Europe but trailing behind the 1,150ft high mechanical rides at the Stratosphere Hotel in Las Vegas, Nevada. (Photo by Huub Zeeman/SWNS.com)

An employee of a bakery talks on his mobile while balancing on his head a tray of freshly baked bread from a local bakery in a street in Cairo, Egypt, January 12, 2016. (Photo by Asmaa Waguih/Reuters)

A worker walks through a salt pan on the eve of May Day or Labour Day on the outskirts of the southern Indian city of Chennai April 30, 2014. India is the third largest salt producing country in the world after China and U.S. with global annual production about 230 million tonnes, according to government data. (Photo by Reuters/Babu)

Konishiki “The Dumptruck” of Hawaii stares down at his opponent during the first Sumo Bashai held outside Japan, at the Albert Hall in London, England. (Photo by Chris Cole /Getty Images). 1991

Fireworks explode over Elizabeth Tower housing the Big Ben clock in London. (Photo by Kirsty Wigglesworth/Associated Press)

A man hugs a child at the Santuario de Nuestra Senora de Guadalupe during a celebration on the Virgin of Guadalupe Day in Guatemala City, December 12, 2015. According to Catholic believers, December 12 marks the anniversary of the apparition of the Virgin of Guadalupe at the Cerro del Tepeyac in Mexico. (Photo by Jorge Dan Lopez/Reuters)

A hippopotamus performs during a show at the circus in Krasnoyarsk, Siberia, Russia, July 7, 2016. (Photo by Ilya Naymushin/Reuters)

A tourist poses on the glass-bottom bridge at Zhangjiajie Grand Canyon on August 20, 2016 in Zhangjiajie, Hunan Province of China. The Zhangjiajie Grand Canyon's glass-bottomed bridge welcame its trial operation on Saturday and about 8,000 tourists crowded to view the grand glass bridge. (Photo by VCG/VCG via Getty Images)