People take pictures near a Soviet flag flying on an embankment in Saint Petersburg, Russia on June 17, 2023. The flags of Russia, the USSR, and the Russian Empire were installed on the shore to mark the anniversaries of each flag's adoption. (Photo by Anton Vaganov/Reuters)

Mike De Paola, founding director of TW Fine Art, is seen near an art installation at “Feltz Bagels”, a bagel bakery made entirely from felt, at TW Fine Art in Montauk, New York, U.S. August 11, 2023. (Photo by Roselle Chen/Reuters)

A woman looks on while a horse-drawn carriage passes by Italian artist Emilio Ferro's artwork installation “Portal of Light” at the Giza pyramids necropolis during the second edition of the Art D’Égypte exhibition “Forever is Now” on October 27, 2022. (Photo by Khaled Desouki/AFP Photo)

A visitor stands near an art installation portraying China's President Xi Jinping, U.S. President Donald Trump and Russia's President Vladimir Putin during the ARTSUBS exhibition in Surabaya, Indonesia on August 2, 2025. (Photo by Juni Kriswanto/AFP Photo)

A visitor walks past an installation artwork entitled “Confuciuse” which combines the word “Confucius” and “confuse” in the contemporary art exhibition at “Fun and Art” Festival on December 13, 2008 in Xian of Shaanxi Province, China. (Photo by China Photos/Getty Images)

The Prague astronomical clock, or Prague orloj, is a medieval astronomical clock located in Prague, the capital of the Czech Republic. The clock was first installed in 1410, making it the third-oldest astronomical clock in the world and the oldest one still working.