Guests arrive for the opening ceremony of the 23rd Life Ball in Vienna May 16, 2015. Life Ball is Europe's largest annual AIDS charity event and takes place in Vienna's city hall. The Life Ball is a charity gala to raise money for people living with HIV and AIDS. (Photo by Leonhard Foeger/Reuters)

Željava Air Base, situated on the border between Croatia and Bosnia and Herzegovina under Plješevica Mountain, near the city of Bihać, Bosnia, was the largest underground airport and military air base in the former Yugoslavia, and one of the largest in Europe. (Photo by Thomas Windisch/Exclusivepix Media)

A soldier helps another with her ear protection at the Terningmoen Camp in Elverum, Norway on March 23, 2017. Soldiers demonstrate their skills and tactics during a contract drill as they train to become part of the world's first all-female special forces unit, the Jegertroppen or “hunter troops”. (Photo by Carolina Reid/NBC News)

The 6th Siberian Tattoo Festival at Podzemka Loft Park in Novosibirsk, Russia on August 20, 2017. Tattoo lovers have been showing off their impressive inkings at annual conventions in LA and Russia this weekend. This year marks the sixth Siberian Tattoo Festival in Novosibirsk, Russia, while stateside tattoo fanatics have been celebrating all things body-art at the LA Tattoo Convention in Long Beach, California. (Photo by Kirill Kukhmar/TASS)

A woman gets a pedicure in Port-au-Prince, Haiti, on October 13, 2017. (Photo by Andres Martinez Casares/AP Photo)

A boy shoots a World War II machine gun armed with blanks at an weapon exhibition during a military show near Kirovsk, about 30 kilometers (19 miles) east of St. Petersburg, Russia, Sunday, January 21, 2018. (Photo by Dmitri Lovetsky/AP Photo)

A woman is detained by security forces after looting broke out during an ongoing blackout in Caracas, Venezuela, March 10, 2019. (Photo by Ivan Alvarado/Reuters)

A person walks their dog in the morning mist at sunrise in Greenwich Park in south London on November 9, 2020. (Photo by Daniel Leal-Olivas/AFP Photo)