Prague is the capital of Czech Republic and, in my opinion, one of Europe’s most beautiful cities. I visited it last month and I loved it. I’m sure I’ll be back.

The historic center is gorgeous, with exceptional buildings, an imposing castle and a bridge which is one the world’s most famous. The whole historic center has been a UNESCO World Heritage Site since 1992.

The astronomical clock
The astronomical clock

Location of the clock

The city of Prague has two banks, divided by the Vltava river:

  • On one side, Malá Strana and Hradcany – The Castle is located in this side;
  • In the other bank: Staré Mesto (old city), Nové Mesto (new city), Josefov (Jewish quarter) and Vysehrad.

On the facade of the old City Council, located in the city’s heart (old town), we can find one the most emblematic points of Prague. It’s the astronomical clock, one of the world’s oldest and most elaborate. In addition to telling the time, it also shows the moon phases and movement of the stars… It’s a monument to sky observation.

Actually, the main function of the astronomical clock was to describe the movement of the celestial bodies, showing the time was just a secondary element…

I’ve passed by it several times and the number of tourists looking at it and photographing it is unbelievable. This building is being repaired since June 2017, the access to its interior is closed to the public and the outer side is partially covered. You will see that in this article’s photos.

If you are thinking about going to Prague, do it next year preferably. The works will finish at the end of 2017.

The construction of the clock

The building of the City Council was created in 1338 and its initial goal was to be the administrative headquarters of the old town. Some years later, a tower was added to its southern part. In 1410 the astronomical clock was installed in its facade.

This masterpiece was achieved by the royal clockmaker Mikuláš de Kadaň and was perfected, at the end of the 15th century, by the hands of the master Hanuš de Růže. There is a legend that says that Hanuš built the clock, but this is not true. The legend also affirms that, in order to ensure that the clockmaker wouldn’t build an identical clock, the counselors of Prague gave the order to blind him. But, in a revengeful act, Hanuš stopped the clock…

In reality, the astronomical clock stopped indeed, but that happened many years later, already in the 19th century. Its mechanism was repaired by the clockmaker Ludvík Hainz.

Prague was constituted by 4 cities which, in the 18th century, came together and so the City Council became the city’s headquarters. Back then, a proposal to remove the clock from the tower’s facade was made. Fortunately it was not accepted.

Since then, several actions were conducted to enhance the clock, in order to preserve it and improve some mechanisms. Even though the clock already has several centuries of age, some parts of it are still the original ones.

The 3 parts of the astronomical clock

Part 1 – The 12 Apostles

On the top, there are 12 mechanical statues which depict the 12 apostles. These images were added to the watch in the 17th century. During the fire of 1945, these statues were destroyed, having been replaced by wooden statues made by Vojtěch Sucharda 3 years later.

When the clock strikes the hour, between 9 am and 11 pm, you can see a parade of statuettes in 2 small windows under the roof. You will recognize each of the apostles, since they have attributes that make them identifiable.

In addition to the apostles who show up every time the clock strikes the hour, some other statues also “come to life”. The skeleton, which has in its hand an hourglass that measures time, pulls the thread and unleashes the parade. It nods its head to the Turkish, who symbolizes extravagance. The Turkish refuses it.

The miser moves his head and shakes his cane and bag, as a threatening gesture, while, right by his side, the statue that represents vanity is looking itself in the mirror. These figures are symbols of Prague’s medieval society.

When the rooster sings, all movements come to an end and the astronomical clock sleeps for another hour.

Part 2 – The astronomical display

The astronomical clock has more than 600 years of age and is unique in the world. From its astrolabe we can get different sorts of information. The astrolabe is an astronomical instrument used to determine the local time, as well as the position of the sun, moon and stars.

What exists in the tower of the old Prague City Council is an enormous circle with 2 circular discs kept together in the center. The upper part represents the day and the lower part the night. In the lower part we can see 2 colors with the sunrise and the sunset, on the left and on the right, respectively. One just needs to look at the position of the sun and we can confirm what time of the day we currently are!


When looking closely to the astrolabe we can also be acquainted with:

  • The time of the old Bohemian – Gothic numbers indicate the hours that have passed since the sunset, which was the beginning of the new day;
  • The time of Babylon – the Arab numbers measure the hours between the sunrise and the sunset, therefore the summer and winter days have different lengths;
  • The time of Central Europe or the Old German Time – the golden hand indicates the time used by all of us. The day starts at midnight;
  • The time of the Stars – it’s shown on the Roman numeral display and derives from the movement of the stars;
  • The sunrise and sunset – the location of the sun in the regions of 3 different colours indicates if it’s day or night. The sunrise and sunset happen in the boundaries of these colours;
  • The Zodiac signs – marked by the 12 zodiac symbols;
  • The position and phases of the moon – a ball travels through the display, performing a round of 29 and a half days (lunar month), changing its aspect based on the phases of the moon;
  • The declination of the sun – based on the position of the sun on the golden circles, which represent the Tropic of Cancer, Capricorn and the Equator;
  • The equinox and solstice – based on the position of the sunlight on the bars that connect the Zodiac ring to the clock.

This is the medieval perception of the universe.

Part 3 – Display of the calendar

This is the newest part of the astronomical clock, having been added to it in the 19th century.

The most important part is the Cisiojanus. This is the mnemonic display used to remember the most important festivities on a certain day of the month. This information is found on the outer ring. The man responsible for this device was Karel Jaromír Erben, a Czech historian, poet and writer.

On the calendar’s display there is also information on the zodiac signs, as well as on the days and months of the year. To verify the current date one just needs to check what’s at the top.

In addition the symbol of the old city, we also find statues of the philosopher and Archangel Michael, an astronomer and chronicler.

Calendar display
Calendar display