An Andean man and a woman, depicting Inca's legendary characters Manco Capac and Mama Ocllo, pose for a portrait in a Uros island at Lake Titicaca before a re-enactment in Puno November 5, 2014. The Uros islands are a group of 70 man-made totora reed islands floating on the lake, which according to Peru's tourism board iPeru is the world's highest navigable lake at over 4,000 meters above sea level. The Uros people fish and hunt, but tourism is their main source of livelihood. (Photo by Enrique Castro-Mendivil/Reuters)

Pedestrians and traffic cross Tower Bridge as viewed through a glass viewing platform on the high-level Walkways during a preview to launch the new viewing experience at the Tower Bridge Exhibition centre in London on November 10, 2014. The new glass flooring at the Tower Bridge Exhibition 42 metres above the river Thames will allow visitors to gaze down on the bridge and river and allow them to experience the bridge opening from above. (Photo by Andrew Cowie/AFP Photo)

An art installation formed with milk churns, made by land art artist Gerard Benoit a la Guillaume, is seen at the Chenau de Mayen in the resort of Leysin, Switzerland August 7, 2015. More than 80 milk churns were placed between the Tour d'Ai and the Tour de Mayen summits at an altitude of 2,000 meters (6,561 feet) above sea level under the direction of the artist, to be photographed for his ongoing art project entitled “Milk churns without borders”. (Photo by Denis Balibouse/Reuters)

Image of the Clouds taken in August 2014 by astronauts on board the International Space Station (ISS). A year from space photographs of hurricanes, typhoons and meteorite craters show an astronauts-eye view of our planet from hundreds of miles above the earth. The illuminating images were taken by astronauts onboard the International Space Station (ISS) over the course of 2014. (Photo by NASA/SPL/Barcroft Media)

Two rainbows emerge from a black storm above the mountains, on August 19, 2014, in Kingman, Arizona. Double tornadoes, lightning storms and rotating supercells – this is what it's like to chase storms for a year. These dramatic images show apocalyptic weather throughout 2014 from a lightning storm to a pair of rainbows. Roger Hill, 57, has been chasing storms in the United States for thirty years and runs a tour operation with his wife Caryn. His favourite photograph of the year was also one of the most difficult to get – as two violent tornadoes tore through Pilger, Nebraska on June 16. The spiraling winds killed a five-year-old girl and injured at least 19 others, and as Roger tried to get the perfect shot debris began to rain down on his car. (Photo by Roger Hill/Barcroft Media)

A tourist walks inside the Ice Palace glacier hollow at Hintertux glacier, located at around 3250 meters above sea level, in Zillertal, Austria, 02 March, 2016. The hollow's temperature remains constant at 0 degrees Celsius, in summer and winter alike, and is also used by the University of Innsbruck for scientific research projects. (Photo by Lisi Niesner/EPA)

People walk along the Dune du Pilat (Dune of Pilat), the tallest sand dune in Europe, in La Teste de Buch, near Bordeaux, France, June 15, 2016. The dune has a volume of about 60,000,000 m³, measuring around 500 m wide from east to west and 2.7 km in length from north to south. Its height is currently 110 meters above sea level. (Photo by Sergio Perez/Reuters)

In this Monday, July 25, 2016 photo, skydiver Luke Aikins smiles as he jumps from a helicopter during his training in Simi Valley, Calif. After months of training, this elite skydiver says he's ready to leave his chute in the plane when he bails out 25,000 feet above Simi Valley on Saturday. That's right, no parachute, no wingsuit and no fellow skydiver with an extra one to hand him in mid-air. (Photo by Jae C. Hong/AP Photo)