The Prague Astronomical Clock (or Prague Orloj) is one of the most iconic landmarks in the city, drawing crowds from all over the world to the city’s Old Town Hall every hour. It’s a masterpiece of medieval engineering—a blend of timekeeping, astronomy, and art. If you’re in Prague, standing in the Old Town Square to watch the hourly show is a quintessential experience. Here we look at the clock’s history, and how it works, in a bit more detail.
Brief History of the Prague Astronomical Clock
The Prague Astronomical Clock was installed in 1410, making it one of the oldest working astronomical clocks in the world. However, other similar examples do exist – for instance in Poznan, where two goats come outside and fight with their horns!
Prague’s clock was created by Mikuláš of Kadaň, a clockmaker, and Jan Šindel, a professor of astronomy at Charles University. The clock was designed to serve not just as a timepiece, but as a tool for both astronomical and calendar-based functions.
Over the years, the clock has undergone several renovations and repairs, including a significant overhaul in the 16th century. Despite the passage of time and the changes the clock has experienced – including the Nazi occupation of Prague – it remains a functioning medieval mechanism, still operating with remarkable precision. If you take the Prague Old Town Hall tour you can see behind the clock face and take a peek at the mechanism and the Saints waiting to come out.
The Design and Function: A Mechanical Marvel
At its core, the Prague Astronomical Clock is more than just a standard timekeeper. It’s a sophisticated combination of several clocks and displays, each designed to show a different aspect of time.
The Dial and Timekeeping
The main feature of the clock is the astronomical dial, which shows the positions of the sun and moon, and the Zodiac signs. The outer ring tracks the hours of the day, while the inner ring shows the time in medieval Bohemian hours, a system that was used before the adoption of modern timekeeping. This dual system of time, one based on the modern 24-hour day and the other on older timekeeping methods, offers an interesting glimpse into how people once viewed the passage of time.
The sun and moon move across the dial, with a golden circle representing the sun, and a silver one for the moon, giving the clock its celestial feel. The phases of the moon are also displayed on the dial.
The Calendar Dial
The lower portion of the clock features a calendar dial, a secondary feature that shows the date and the Saint of the Day based on the Christian calendar. The calendar is beautifully decorated with the signs of the zodiac and each month is represented by a figure, such as a farmer or a merchant, in a detailed and artistic design. The calendar dial is one of the more beautiful aspects of the clock, and its fine artwork adds a layer of historical context to the timepiece.
The Moving Figures
Every hour, on the hour, the clock puts on a show. As the clock strikes, you’ll see the 12 Apostles appear in the upper windows, moving in a clockwise direction. The figures could be seen as symbolic of the passing of time and the 12 hours of the day. Each figure takes its turn, looking out over the square as if blessing the city.
The Skeleton and the Hourly Show
Perhaps the most famous aspect of the hourly show is the appearance of a skeleton who pulls a rope to signify the passing of time—this is the embodiment of Death, a slightly macabre reminder of the fleeting nature of life. Enjoy that whilst you’re on a romantic trip to Bohemia! Alongside it, the clock features other figures, such as Vanity, represented by a figure looking in a mirror, and Greed, symbolized by a figure with a bag of coins.
As the Apostles make their appearance, you’ll also hear the chimes of the clock ringing out. The mechanical chime is part of the original design, adding an atmospheric layer to the experience. While the show lasts only about a minute, it’s always a crowd-pleaser, and you’ll see a lot of visitors gathering in the Old Town Square to watch the spectacle. It can get pretty busy so be warned!
Why Prague’s Astronomical Clock Is So Special
The Astronomical Clock isn’t just a functioning timepiece—it’s a symbol of Prague’s rich history, one that combines art, science, and medieval craftsmanship. It’s also an excellent example of how medieval technology was often intertwined with astrology, religion, and daily life. Maybe we’ve lost this to some extent in the modern “clean lines, function first” type design that so often wins out?
The clock’s design was ahead of its time, using sophisticated mechanisms that were arguably centuries ahead of similar devices elsewhere in the world.
The clock’s hourly show, with its moving figures and eerie skeleton, also maybe reflects a deep cultural awareness of mortality—something that was always on the minds of people in the Middle Ages, when life expectancy was much lower, death was ever-present and heaven and hell we’re real concepts to a larger proportion of people than in lots of Europe today.
Visiting Prague’s Astronomical Clock
If you’re in Prague, don’t miss the opportunity to see the Prague Astronomical Clock in person. The best time to visit is just before the hour, when crowds gather in the Old Town Square to watch the show. You’ll find the Old Town Hall in the square, where the clock is located, and it’s usually easy to spot a crowd forming as the time nears.
While the hourly show is a must-see, consider taking a moment to appreciate the clock’s intricate details from a distance – or close up when it’s not near the hour and the crowds are slightly thinner. Its elaborate carvings, gothic architecture, and astronomical dials are a testament to the ingenuity of its creators.
For those interested in learning more about the clock and its historical significance, you can even take a guided tour of the Old Town Hall and learn more about the Orloj’s fascinating past. The clock’s unique blend of art and science makes it a standout piece of Prague’s history—and its timeless beauty continues to captivate visitors from around the world.
It’s a piece of Prague that never stops ticking, always reminding us of the passage of time—and the beauty of the city that holds it.
