Men slide in the mud during the Boryeong Mud Festival at Daecheon Beach in Boryeong, South Korea, Saturday, July 22, 2017. The 20th annual mud festival features mud wrestling and mud sliding. (Photo by Ahn Young-joon/AP Photo)

As the sun sets on the Malecon in Havana on Friday January 23, 2015, Surenis Angulo de la Paz, 24, center, dances as group of locals play music around her. Behind her is Fidel Lopez, 55. (Photo by Sarah L. Voisin/The Washington Post)

Residents of the Brussels suburb of Molenbeek are searched by police before taking part in a memorial gathering to honour the victims of the recent deadly Paris attacks, in Brussels, Belgium, November 18, 2015. (Photo by Yves Herman/Reuters)

Ukraine's Ruslana performs her song Wild Dance ands wins the Eurovision Song Contest on May 15, 2004 at the Abdi Ipekci Stadium, in Istanbul, Turkey. The event – hosted by last year's winners Turkey – also celebrates the 30th Anniversary of ABBA's win. (Photo by Christopher Furlong/Getty Images)

Angel Paz, dressed as a calavera, waits with family for the start of the Gran Procession of the Catrinas, to mark the upcoming Day of the Dead holiday, in Mexico City, Sunday, October 23 2016. (Photo by Anita Baca/AP Photo)

A boy carries sugar cane through a farm on the outskirt of Zaria in Nigeria's northern state of Kaduna November 15, 2016. (Photo by Akintunde Akinleye/Reuters)

Rays from the rising sun shine through the foliage of trees as fog covers the ground near the Guckler Karoly Observatory in Budapest, Hungary, 02 January 2017. (Photo by Balazs Mohai/EPA)

Only 156 people remained in the tribe when Jan visited in Accham District, Nepal, January 2016. Hidden deep in the Himalayan forest is one of the world’s last enduring nomadic tribes who are resisting attempts to move them into permanent settlements. (Photo by Jan Moller Hansen/Barcroft Images)