Revellers cool themselves in the Danube River during the Sziget music festival on an island in Budapest, Hungary August 12, 2015. The event is one of the biggest cultural events of Europe, offering art exhibitions, theatrical and circus performances and music concerts. Almost 200 performers from 47 countries will entertain the hundreds of thousands of visitors from 11 to 18 August. (Photo by Laszlo Balogh/Reuters)

Spanish Patrulla Aguila (C-101), aerobatic demonstration team of the Spanish Air Force performs during the Radom Air Show at an airport in Radom, Poland August 23, 2015. (Photo by Kacper Pempel/Reuters)

American students going wild during their Spring Break week-long recess in Cancun, Mexico on March 10, 2007. (Photo by Keystone USA/ZUMA Press/Rex Features/Shutterstock)

A dog with a cherry blossom-shaped pin, is seen in the cherry blossom festival in Seoul, South Korea, Sunday, April 9, 2017. (Photo by Lee Jin-man/AP Photo)

Dressed for the traditional New Year's festival known as “La Diablada”, in Pillaro, Ecuador, Friday, January 5, 2018. Thousands of singing and dancing devils take over the mountain town for six days of revelry in the streets. Local legend holds that anyone who adopts a costume for the celebration and wears it at the event six years in a row will have good luck. (Photo by Dolores Ochoa/AP Photo)

Dancers at the Windmill Theatre in London, England practice a routine wearing gas masks and hard-hats with their costumes, 1940. (Photo by Hulton Archive/Getty Images)

In this Thursday, May 24, 2018, photograph, artists of Ukraine's Artel Myth theatre perform “A day in the life of Ukrainians” at the Living Statues International Festival, in Bucharest, Romania. Up to thirty thousand people enjoyed a week of street performances by reputed artists from eight countries in the “largest European festival of the genre”. (Photo by Vadim Ghirda/AP Photo)

A demonstrator is carried away by plain-clothes police during a march against government reforms and cost-cutting measures in Brussels , October 7, 2015. (Photo by Francois Lenoir/Reuters)