Set into the southern wall of the Old Town Hall in Prague’s Old Town Square, the Astronomical Clock dates to 1410 and is still in operation. Its dial tracks the sun and moon, while a calendar face marks the days and months. On the hour, moving figures appear in a brief procession, ending with a rooster’s call. Look closely at the clock’s painted details, then consider going up the Old Town Hall Tower for a view over the square and Prague’s rooftops.
A clock on the Old Town Hall
The Astronomical Clock, known in Czech as Pražský orloj, is mounted on the southern wall of the Old Town Hall in Old Town Square. First installed in 1410, it is among the world’s oldest astronomical clocks and the oldest still operating. The clock has been repaired and maintained over centuries.
The Old Town Hall complex began after Prague received permission to form a city council in 1338. Its main building and tower were completed before the clock was added. The tower is also a viewing point, with a lookout over the square and the city’s rooftops.
Reading the dials
The upper dial is an astronomical display. It shows the positions of the sun and moon and includes information about the zodiac and the time. The clock represents several systems of time, including Babylonian time, Old Bohemian time and sidereal time. It also indicates sunrise and sunset and the moon’s phases.
Below it, the calendar dial marks the date. Its medallions represent the months of the year, with a symbol of the Old Town at the centre. The clock is both a timepiece and a record of the astronomical knowledge built into its design.
The hourly procession
At the turn of the hour, the clock’s moving figures begin their short procession. The Twelve Apostles pass through windows above the dial. Other figures include Death, who rings a bell and turns an hourglass, and allegorical figures associated with Vanity, Greed and Pleasure. The display ends with the rooster’s call.
The performance lasts less than a minute, so arrive a little before the hour if you want a clear view. The square becomes crowded around the show. In the evening, the illuminated clock and tower can be seen against the darker sky; early morning is another option for a quieter look at the details.
Häufige Fragen
Where is the Prague Astronomical Clock?
It is mounted on the southern wall of the Old Town Hall in Prague’s Old Town Square.
When does the clock show take place?
The moving figures appear at the turn of the hour. The procession lasts less than a minute.
How long should I allow for a visit?
Allow around 15 to 30 minutes to study the clock and watch the procession. Add time if you plan to go up the Old Town Hall Tower.
What does the Astronomical Clock show?
Its dials display astronomical information, including the positions of the sun and moon, alongside time and date details.
