A worker wearing a protective mask uses a blower to remove leafs from a walkway during sunny autumn weather near Stallikon, Switzerland on October 27, 2020. (Photo by Arnd Wiegmann/Reuters)

Shura Kitata of Ethiopia runs past cardboard cut-outs of the Duke of Cambridge and the Queen at the London Marathon in London, Britain, 04 October 2020. (Photo by Tom Jenkins/The Guardian)

Mr. Grindell Matthews with his latest invention, the new photographic gun which is the latest development in sky signs. 1933. It can throw a beam of light 15 miles into the sky. (Photo by Fox Photos)

German flying ace Baron Manfred von Richthofen (1892–1918) also known as The Red Baron with his dog Moritz, circa 1916.

Urban photographer Roman Robroek spent five years scouring the continent for the grandest examples of forgotten architectural beauty. Here: Watch your step on this Polish spiral staircase. (Photo by Roman Robroek/South West News Service)

German field telegraph operators at work in Warsaw. (Photo by Hulton Archive/Getty Images). 1st October 1914

Dancers wait in the wings before performing in a full-dress rehearsal at the Moulin Rouge in Paris on September 8, 2021, two days ahead of the reopening of the cabaret following an 18-month closure amid the COVID-19 pandemic. Closed for a year and a half due to the pandemic, the Moulin Rouge and Le Lido, emblems of the crazy Parisian nights since 1889, are finally reopening. (Photo by Christophe Archambault/AFP Photo)

An installation of Canadian artists Caitlind Brown and Wayne Garrett is displayed during the Lumina Light Festival in Cascais September 14, 2014. Lumina Light Festival shows artworks of artists from several countries, which are displayed during a tour around Cascais. (Photo by Rafael Marchante/Reuters)