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)

Victor Peralta from Uruguay gestures during the fourth International Tattoo Convention in Quito, September 25, 2016. (Photo by Kevin Granja/Reuters)

A person poses on the track during a fashion competition at the Durban July horse racing event in Durban, South Africa, July 2, 2016. (Photo by Rogan Ward/Reuters)

Winner of the Sandow bodybuilding competition, Mr. Murray. (Photo by Reinhold Thiele/Thiele/Getty Images). Circa 1905

Women sunbath as Ferrari's Brazilian driver Felipe Massa drives past during the third practice session at the Circuit de Monaco in Monte Carlo on May 25, 2013 ahead of the Monaco Formula One Grand Prix. (Photo by Alexander Klein/AFP Photo)

In this photo taken Tuesday, April 14, 2015, immigrant men armed with machetes make their way onto a Durban, South Africa, street during clashes with police and in search of locals that attacked foreign shop owners in the city center. (Photo by Tebogo Letsie/AP Photo)

A visitor holds up her toy bunny to the aquarium glass in front of Aurora the Russian polar bear at the Sao Paulo Aquarium in Sao Paulo, Brazil, Thursday, April 16, 2015. (Photo by Andre Penner/AP Photo)

Raising a flag over the Reichstag is a historic World War II photograph taken during the Battle of Berlin on 2 May 1945, by Yevgeny Khaldei.