A Spanish national police officer uses his club to hit a protester during a demonstration called the Catalan pro-independence left youth group “Arran” on October 19, 2019 in Barcelona, a day after nearly 200 people were hurt in another night of violent clashes in Catalonia. The deterioration came on the fifth consecutive day of protests in the Catalan capital and elsewhere over a Spanish court's jailing of nine separatist leaders on sedition charges over a failed independence bid two years ago. (Photo by Josep Lago/AFP Photo)

A man rides a bicycle by a graffiti under the “Old Sava bridge” over Sava river in Belgrade, Serbia, Wednesday, May 19, 2021. (Photo by Darko Vojinovic/AP Photo)

A supporter of the team of Ukraine cheers prior to the Euro 2016 Group C soccer match between Ukraine and Poland at the Velodrome stadium in Marseille, France, Tuesday, June 21, 2016. (Photo by Thanassis Stavrakis/AP Photo)

Zombie Punk stands for a photo during the International tattoo convention at Tobacco Dock in east London, Friday, September 27, 2019. (Photo by Aaron Chown/PA Wire Press Association via AP Photo)

Graduates dance as they take part in a “Last school bell” ceremony at a school in Minsk, Belarus on May 30, 2018. (Photo by Vasily Fedosenko/Reuters)

Mural of wartime leader Sir Winston Churchill wearing stockings and suspenders and giving the “V” sign by illusive local artist who goes by the name Horace, on the side of the Sandpiper guest house in Brighton on November 22, 2020. (Photo by Gareth Fuller/PA Images via Getty Images)

A Sadhu, or a Hindu holy man, performs yoga on International Yoga Day at Kamakhya temple in Guwahati, India on June 21, 2018. (Photo by Anuwar Hazarika/Reuters)

“Catch of the Decade”. Can you guess what happened next? Photo location: Katmai National Park, Alaska, USA. (Photo and caption by Aaron Baggenstos/National Geographic Photo Contest)