Clementinum Prague: baroque library
Baroque library, astronomical tower, tickets and updated opening hours
Tareq Maanan
Founder and guide at ODISEA. I came to Prague more than 10 years ago and never left. Over 5,000 tours later, the city still surprises me. I write these articles for the same reason I guide: so that nobody leaves Prague with the brochure version.
March 10, 2026 · 9 min readIf you have seen on Instagram a photo of a hall with golden bookshelves reaching the ceiling, antique terrestrial globes and a baroque fresco covering the entire vault, it was probably the Baroque Library of the Clementinum in Prague.
But most travellers arrive without a clear idea of what the Clementinum actually is, whether you can enter the library, how much it costs, or how the visit works. Many confuse it with the Tower of Books, which is something completely different.
Our guides walk past the Clementinum every day. It is on Karlova street, right on the route between Old Town Square and Charles Bridge: you literally walk past without knowing what you are missing. In this article we explain what it is, how to visit it and whether it is worth the price.
What is the Clementinum?
The Clementinum (Klementinum in Czech) is the second largest building complex in Prague after the Castle. It covers more than 20,000 m², an entire city block, and from the outside it looks like just another Old Town building. But inside it is a different story.
It was founded by the Jesuits in 1556 as a college. Over more than 200 years they expanded it into a massive complex that included churches, libraries, observatories and study halls. When the Jesuit order was dissolved in 1773, the building passed into state hands.
Today it is the headquarters of the National Library of the Czech Republic , an active institution with millions of volumes. But what you come to see as a traveller is concentrated in four spaces:
The Baroque Library. The famous hall: golden bookshelves, historic globes and ceiling frescoes representing the Temple of Wisdom. It was completed in 1727 and holds around 20,000 volumes, mostly theology.
The Astronomical Tower. 68 metres tall, with 172 steps up to the viewing balcony at 52 metres and panoramic views of the Old Town. At the top, a statue of Atlas holds a celestial sphere.
The Meridian Hall. On the second floor of the tower. For centuries, solar noon was measured here by a ray of sunlight crossing the hall along the "Prague meridian". It keeps period astronomical instruments.
The Mirror Chapel (Zrcadlová kaple). A baroque chapel from 1724, with faux-marble walls and mirrors in its decoration. Today it is used as a classical music concert hall.
The baroque library: what you need to know
The ceiling frescoes were painted by Josef Hiebel, allegories of science and art under the title "Temple of Wisdom". The terrestrial globes in the centre of the hall are originals from the 18th century.
But there are three things you need to know before going:
You cannot enter the hall. The Baroque Library is observed from the doorway. You look inside, but you do not walk among the bookshelves. It is an active hall of the National Library.
It can only be visited with a guided tour. You cannot enter the Clementinum independently. The only way in is the guided tour, which lasts about 45 minutes.
Photography is strictly prohibited inside the Baroque Library. The images you see on Instagram are promotional or taken with special permits.
Note: do not confuse it with the Tower of Books
This is important because it happens constantly. Many travellers confuse the Clementinum with the Tower of Books (Idiom), the contemporary art installation by Matej Krén consisting of 8,000 stacked books with mirrors that create an infinite tunnel effect.
They are completely different things:
- Idiom is in the Municipal Library of Prague (a different building). It is free, self-guided and takes 10-20 minutes.
- The Clementinum is the National Library. It is paid, visited with a guide and lasts about 45 minutes.
The detail that creates the confusion: both buildings are in the same square (Mariánské náměstí), less than 1 minute walking from each other. But they are different institutions with different experiences. If you want to see both, perfect, but organise them separately.
The astronomical tower of the Clementinum
The astronomical tower is the second part of the guided tour, and for me, the one that surprises people the most.
You climb 172 steps up a narrow staircase to the circular balcony at 52 metres high. The views are panoramic: the red rooftops of the Old Town, the church towers, Charles Bridge in the background, and on clear days you can make out Prague Castle on the other side of the river.
But the most striking fact is not the views, it is the history. From this tower, daily meteorological observations have been recorded since 1775. Without interruption. It is one of the longest continuous meteorological records in the world, more than 250 years of data on temperature, pressure and precipitation at the same exact point.
The tower is included in the same ticket as the Baroque Library. You do not need to buy a separate entry.
Practical note: the stairs are narrow and steep. It is not accessible for people with reduced mobility nor advisable with pushchairs. If you suffer from vertigo or knee problems, bear that in mind before climbing.
Tickets and opening hours for the Clementinum
The guided tour of the Klementinum includes three stops: Baroque Library, Meridian Hall and Astronomical Tower. Tours depart every 20-30 minutes in Czech and English.
Prices 2026
| Category | Price (CZK) | Price (~EUR) |
|---|---|---|
| Adult | 380 | ~16€ |
| Young person (16-26 years) | 300 | ~12€ |
| Child (6-15) / Senior (65+) | 230 | ~€9 |
| Children up to 5 | Free | – |
| Family (2 adults and up to 4 children) | 810 | ~€33 |
Early bird discount: the first two tours of the day (09:00 in English and 09:30 in Czech) are 50% off. Places are few and sell out quickly.
Opening hours
| Period | Hours |
|---|---|
| January - October | 09:00-20:00 |
| November - December | 08:00-21:00 |
Tour duration: about 45 minutes. Hours change over Christmas: check the Prague City Tourism website.
How to buy
Tickets are purchased as eTickets. Every Monday new tickets are released for the following 2 weeks. Capacity is limited; in high season (June to September) they sell out quickly.
Recommendation: buy online several days in advance. If you go in summer and turn up without a reservation, you may not get a ticket that day.
How to get to the Clementinum
Address: Klementinum 190, Staré Město (Old Town), Prague 1.
It is on Karlova street (Karlova ulice), which is the pedestrian road connecting the Old Town Square with the Charles Bridge. If you walk from one to the other, you pass in front of the Clementinum without realising it; it is one of those enormous buildings that blend in with the rest of the street.
| From | Walking time |
|---|---|
| Tram Karlovy lázně | ~1 minute |
| Old Town Square | ~3 minutes |
| Charles Bridge | ~2 minutes |
| Metro Staroměstská (Line A) | ~2 minutes |
There is no car access; the entire area is pedestrianised. The nearest tram stop is Karlovy lázně, and the closest metro station is Staroměstská on Line A (green).
Concerts in the Mirror Chapel
The Mirror Chapel hosts classical music concerts very frequently, with works by Mozart, Vivaldi, Dvořák and Smetana.
The concerts are independent of the guided tour to the Baroque Library; they are purchased separately and accessed through a different entrance. You can do both on the same day, but you need two separate tickets.
Visit with ODISEA Tours
Our Malá Strana and Charles Bridge free tour ends right here: after crossing Charles Bridge, the route finishes next to the Clementinum and the Municipal Library, home of the Tower of Books. The guide tells the building's Jesuit history and clears up the confusion between the two libraries.
To see the interior (the Baroque Library and the Astronomical Tower) you need the separate guided tour: we do not go inside during the free tour.
Our recommendation: do the free tour first and visit the Clementinum afterwards. With the context of baroque Prague and the Jesuits, the library makes much more sense; without it, it is beautiful but you do not know what you are looking at. All our routes are in our guide to free tours in Prague.
Frequently asked questions
Can you visit the Clementinum library independently? No. Only with a guided tour (about 45 minutes). You observe the Baroque Library from the doorway; you cannot walk through the hall. The tour also includes the Astronomical Tower and the Meridian Hall.
How much does entry to the Clementinum in Prague cost? Adult: 380 CZK (~€16). Young people aged 16 to 26: 300 CZK. Children aged 6 to 15 and over-65s: 230 CZK. Family (2 adults and up to 4 children): 810 CZK. Up to 5 years old, free. The first two tours of the day are 50% off.
How long does the Clementinum visit last? About 45 minutes. It includes the Baroque Library, the Meridian Hall and the climb up the Astronomical Tower (172 steps).
Can you take photos in the Clementinum library? No. Photography is strictly prohibited inside the Baroque Library. The photos you see on social media are promotional or taken with special permits. Rules may vary in the tower and the Meridian Hall; ask the guide.
Is the Clementinum worth visiting? Yes. The Baroque Library is one of the most photographed in Europe, with its frescoes, golden bookshelves and 18th-century globes. And the Astronomical Tower offers views few travellers know about: most climb the Town Hall tower next to the Astronomical Clock without knowing this one exists. 380 CZK for three unique spaces is a reasonable price.
What is the difference between the Clementinum and the Tower of Books? They are different attractions. The Clementinum is a baroque complex with a historic library, an astronomical tower and a chapel, visited with a guide and a paid ticket (380 CZK). The Tower of Books (Idiom) is a contemporary art installation made of 8,000 books and mirrors in the lobby of the Municipal Library, and it is free to see. Both are on the same square, Mariánské náměstí.
The Clementinum is 3 minutes from Old Town Square and the Astronomical Clock, and 2 minutes from Charles Bridge. The Tower of Books is literally next door, on the same square. You can combine all three in a morning or, in the afternoon, finish here with our Malá Strana and Charles Bridge free tour.