This is the Prague Astronomical Clock, installed in 1410, it's the oldest clock still operating. World's Oldest Working Astronomical Clock Prague's Astronomical Clock is the world's oldest working one of its kind. Installed in 1410, it is located on the Old Town City Hall in Prague's Old Town Square, Czechia. The medieval clock features an astronomical dial; "The Walk of the Apostles", an hourly show of moving sculptures; and a monthly calendar dial with the 12 signs of the zodiac.
