Once the centre of Prague's Jesuit activities, the Klementinum was continually expanded and completed in 1726. Here Mozart performed in the Baroque Chapel of Mirrors, where classical music concerts still take place to honour the composer's memory.
After the Jesuits were disbanded in the mid-18th century, Charles University moved their library to the site and it currently houses the National Library of the Czech Republic and the State Technical Library, with an estimated five million volumes.
In addition to classical concerts, there are guided tours and energetic visitors can climb the tower's 200-odd steps for stunning city views.