Mariánské náměstí 190/5: Klementinum
The Klementinum has always been at the academic heart of Prague. In 1556, when twelve missionaries arrived in the city to found a Jesuit college, they chose as their new home the complex of buildings near the Charles Bridge that had formerly been a Dominican monastery. The Klementinum remained at the centre of Jesuit learning and thought until the dissolution of the order in the 1770s.
In 1722, the chancellor of the university, František Retz, arranged for the construction of a 170-foot high astronomical tower and observatory (above), whose principal role throughout the next two centuries was to determine the exact time of noon in Prague. It is not known who was responsible for the building, though the names usually associated with it include František Maximilían Kanka, Anselmo Lurago, and Kilián Ignác Dientzenhofer. The statue of Atlas bearing an armillary sphere dates from the same time and was cast in the workshop of the sculptor Matthias Bernhard Braun.
The establishment of the tower within the college was hardly surprising. The obsessive astronomical observations of the Jesuits were already marked by the presence of fourteen remarkable wall-mounted sundials dating from the time when the Klementinum was incorporated into Charles University in the 1650s. One is painted on the tower itself; the other thirteen are situated in the various courtyards of the university and library complex. Again, the name of their creator is not recorded, though evidence points towards the Jesuit astronomer Valentin Stansel (1621-1705). A selection of the sundials, with quotations from Psalm 113, is shown below: