The Prague Astronomical Clock, known locally as the Orloj, is set into the southern wall of the Old Town Hall on Old Town Square. Installed in 1410, it is among the world’s oldest astronomical clocks and the oldest still in operation. Its intricate face turns a medieval view of the cosmos into a working instrument, tracking the Sun and Moon against the zodiac.
Below the astronomical dial, a calendar shows the months and saints’ feast days. On the hour, figures come to life around the clock: a skeleton rings a bell and the Twelve Apostles appear in windows above. The mechanism has been repaired and rebuilt over centuries, but its blend of craftsmanship, science and spectacle remains a compelling window into Prague’s history.
Visit early in the day for a less crowded view, and arrive a few minutes before the hour if you want to see the procession. For a closer look at the clock and a panorama over Old Town Square, consider a ticket to the Old Town Hall tower; check current opening times before you go.