A girl jumps over a campfire while celebrating Ivan Kupala Night, a traditional Slavic holiday not far from Kiev on July 6, 2013. During the celebration, originating in pagan times, people plait wreaths, jump over fires, and swim naked. (Photo by Sergei Supinsky/AFP Photo)

The 26th annual National Geographic Traveler Photo Contest is now accepting submissions. Official categories include: “Travel Portraits”, “Outdoor Scenes”, “Sense of Place” and “Spontaneous Moments”. The contest is accepting entries until June 30. Photo: “Forest lights”. Aurora Borealis over the forest of the Pyhae Luosto National Park, Finland. (Photo and caption by Nicholas Roemmelt/National Geographic Traveler Photo Contest)

A girl attends Friday prayers in front of an army tank in Tahrir Square in Cairo February 18, 2011. Five years ago thousands of protesters took to the streets demanding the end of the 30-year reign of President Mubarak as Egypt became the second country to join the Arab Spring. After weeks of clashes, strikes and protests across Egypt, Mubarak resigned on February 11, 2011. (Photo by Suhaib Salem/Reuters)

A doll in a children's gas mask is seen amongst beds at a kindergarten in the abandoned city of Pripyat near the Chernobyl nuclear power plant in Ukraine on March 28, 2016. Deadly radiation still spews from Chernobyl 30 years after the worst nuclear meltdown in history, as a newly built giant arch is pulled into place to cover the stricken reactor for the next century. (Photo by Gleb Garanich/Reuters)

People perform during this year's flashmob of silly walks, based on the sketch from the television show Monty Python's Flying Circus by Monty Python troup, in Budapest, Hungary, 01 April 2019. (Photo by Zoltán Balogh/EPA/EFE)

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)

An inmate covers his head as he passes the time inside Quezon City Jail in Manila, Philippines October 19, 2016. Nearly 2,300 drug users and dealers have been killed in police operations or by suspected vigilantes since Duterte took office on June 30, according to the Philippines police. (Photo by Damir Sagolj/Reuters)

Houses near Taal Volcano's crater are seen buried in volcanic ash from the volcano's eruption on January 14, 2020 in Taal Volcano Island, Batangas province, Philippines. The Philippine Institute of Volcanology and Seismology raised the alert level to four out of five, warning that a hazardous eruption could take place anytime, as authorities have evacuated tens of thousands of people from the area. An estimated $10 million worth of crops and livestock have been damaged by the on-going eruption, according to the country's agriculture department. (Photo by Ezra Acayan/Getty Images)