The Clementium library in Prague is one of the most ornate and elaborate in the world, housing over 20,000 rare and unique books although is relatively unknown outside of the Czech Republic. This despite the fact that the building is the second largest in the entire city behind only Prague castle.
The library was built on the site of a 11th-century chapel dedicated to St Clement, and over the years has also served as a Jesuit college, a monastery and as part of a larger university also housing an observatory.
The site also features a determining room, now known as the Meridian Hall, in which a small ray of sunlight that enters the room through a hole in the wall falls onto a stretched piece of string used to measure when high noon falls.
Today some parts of the site are open to tours, and the site is also the national library of the Czech Republic. The Baroque library, in particular, is known as one of the best-preserved examples of baroque architecture in the world and has won numerous awards as being one of the most decoratively elaborate libraries ever built.
One of the other claims to fame of the 20,000 square meter site is that the observatory was the first place to record the air temperature in Prague in 1775, and the readings have continued to this day. Johannes Kepler also developed his laws of planetary motion at the Clementium, a major astrological achievement of the time.
While this might inspire visitors to the site, however, there appear to be issues with gaining entry at the moment. Entering the library website, visitors are now met with the following:
“We are very sorry to inform you that due to the legal dispute with the National Library of the Czech Republic, administrator of Klementinum, we are not able to guarantee that the guided tours and other services that we provide will také place in the Astronomical Tower, the Baroque Library, and the Mirror Chapel.”
While it isn’t clear what the dispute is or how long it might take to resolve it does mean that visiting the library might not be possible for the time being. There are also certain sections of the building currently under expansion and reconstruction, meaning only library users are currently allowed full access.
More on the history of the Klementium can be found here: http://www.klementinum.com/index.php/en/history