A participant of the Wild Sau Dirt Run 2015 passes a mud barrier in Obertriesting, Lower Austria, Austria, Saturday, April 4, 2015. The Wild Sau Dirt Run is a cross country and steeplechase race for men and women over the distances of 5, 10 and 20 kilometers (3.1, 6.2 and 12.4 miles). (Photo by Ronald Zak/AP Photo)

Colored Pencil and Origami Landscapes: Ivanova's version of the popular Snake game features a chain-link origami snake chasing a butterfly. (Photo by Victoria Ivanova)

British model Demi Rose leaving Bob Bob Ricard on November 20, 2017 in London, England. (Photo by Splash News and Pictures)

Vast collection of fine art photography about to open at Pier 24 in Manhattan. One of the world's most prestigious annual photography events, The Photography Show is the longest-running and foremost exhibition dedicated to the photographic medium, offering a wide range of museum-quality work, including contemporary, modern, and 19th-century photographs as well as photo-based art, video, and new media. Here: Les Trois Femmes Deux, 2018. (Photo by Mickalene Thomas/Courtesy of Yancey Richardson Gallery, New York)

Masked revellers pose during the Venice Carnival in Venice, Italy February 11, 2017. The Venice carnival in the historical lagoon city attracts people from around the world. (Photo by Tony Gentile/Reuters)

Gianluca Pardelli is something of an expert on markets. For the past two years, he’s travelled across eastern Europe, from Azerbaijan to Uzbekistan, Moldova to Georgia, photographing them. Here: Telavi, Georgia. (Photo by Gianluca Pardelli)

In Omdurman, the largest city in Sudan, the Qadiriyya Sufi order meets every Friday outside Sheikh Hamed Al Nil mosque, which houses the tomb of their 19th century Sufi leader. (Photo by Ala Kheir, John Burns and Ibrahim Algrefwi/Brownbook)

Chinese artist Kong Ning poses in a costume symbolizing a butterfly, which is decorated with 365 masks on its wings to represent the number of days in a year, during her performance art at the Badaling section of the Great Wall on the outskirts of Beijing January 1, 2015. Kong, whose works include themes related to China's air pollution problem, named her new performance art “Hua Die” (transforming into a butterfly) and performed it on the first day of the new year as she hopes that China has clean air for this year. (Photo by Kim Kyung-Hoon/Reuters)