The Church of the Holy Cross is a medieval Gothic style building with a peculiar shaped tower. Construction started in the 13th century and was completed in the first half of the 15th century. The church was originally built with a round tower, however during the first half of 17th century half of the top of the tower collapsed.
There are two tombs from the 15th century and a pulpit from the 17th century inside the church.
Reference: 7is7.com
The Clementinum is a historic complex of buildings in Prague. Until recently the complex hosted the National, University and Technical libraries, the City Library also being located nearby on Mariánské Náměstí. The Technical library and the Municipal library have moved to the Prague National Technical Library at Technická 6 since 2009. It is currently in use as the National Library of the Czech Republic.
Its history dates from the existence of a chapel dedicated to Saint Clement in the 11th century. A Dominican monastery was founded in the medieval period, which was transformed in 1556 to a Jesuit college. In 1622 the Jesuits transferred the library of Charles University to the Klementinum, and the college was merged with the University in 1654. The Jesuits remained until 1773, when the Klementinum was established as an observatory, library, and university by the Empress Maria Theresa of Austria.