A participant dances as approximately 70,000 people from all over the world gathered for the annual Burning Man arts and music festival in the Black Rock Desert of Nevada, U.S. on August 29, 2017. (Photo by Jim Urquhart/Reuters)

Revellers dressed in mock military garb take part in the “Els Enfarinats” battle in the southeastern Spanish town of Ibi on December 28, 2017. During this 200-year-old traditional festival participants known as Els Enfarinats (those covered in flour) dress in military clothes and stage a mock coup d'etat as they battle using flour, eggs and firecrackers outside the town hall as part of the celebrations of the Day of the Innocents. (Photo by Jaime Reina/AFP Photo)

A woman leans against one of the stones of the Stonehenge monument on the summer solstice near Amesbury, Britain on June 21, 2017. The annual festival attracts hundreds of people to the 5000 year old stone circle to mark the longest day in the northern hemisphere. sunrise was at 4.52am and was celebrated by dancing, music, and ritualistic events around the stones. (Photo by Neil Hall/Reuters)

Mushers and their huskies practice at a forest course ahead of the Aviemore Sled Dog Rally on January 24, 2016 in Feshiebridge, Scotland. Huskies and sledders prepare ahead of the Siberian Husky Club of Great Britain 34th race taking place at Loch Morlich this weekend near Aviemore. (Photo by Jeff J. Mitchell/Getty Images)

Heidi Klum direct a photoshoot for “Germany's Next Top Model” on set filming on Hollywood Boulevard, Los Angeles, USA on January 25, 2017. (Photo by Splash News and Picture)

A competitor shouts as he takes part in the “Tough Guy” adventure race near Wolverhampton, central England, on January 29, 2017. The Tough Guy event, which is being held for the final time in its 30th year, challenges thousands of competitors to run a gruelling course whilst negotiating over 200 obstacles including: water, fire, and tunnels. (Photo by Oli Scarff/AFP Photo)

Elementary school children play outside their classrooms as mount Sinabung volcano spews thick volcanic ash in the background on February 10, 2017 in Karo, Indonesia. Mount Sinabung is one of the most active volcanoes in Indonesia and last erupted in May 2016, killing seven people. (Photo by Albert Damanik/Barcroft Images)

Actor John Travolta (L) and recording artist Lady Gaga attend Interscope's Grammy After Party with Lady Gaga at the Peppermint Club on February 12, 2017 in Los Angeles, California. (Photo by Christopher Polk/Getty Images for Interscope)