An Iraqi woman attends a festival commemorating the International Day of Peace in Baghdad, September 21, 2015. (Photo by Thaier al-Sudani/Reuters)

A man and his son ride a horse at Tahrir Square in Sanaa, Yemen on January 21, 2021. (Photo by Khaled Abdullah/Reuters)

Some bats in the forested area of Guapiles, Costa Rica, 21 April 2020. (Photo by Jeffrey Arguedas/EPA/EFE)

Christie Brinkley is seen walking in midtown on August 21, 2019 in New York City. (Photo by Raymond Hall/GC Images)

Underground dancers dressed in Spiderman costumes perform in the subway of Saint Petersburg late on May 21, 2021. (Photo by Olga Maltseva/AFP Photo)

An Afghan boy carrying empty plastic cans, walks along a street in Kabul on December 21, 2023. (Photo by Wakil Kohsar/AFP Photo)

A runner in fancy dress participates in the Virgin London Marathon 2013 on April 21, 2013 in London, England. (Photo by Tom Dulat/Getty Images)

Iraqi forces gather during an operation to attack Islamic State militants in Mosul, Iraq, October 21, 2016. (Photo by Reuters/Stringer)