Église Saint-Pantaléon Church was built in the 12th century. The first patron saint was saint Himère. After the epidemic of plague between the years 1337 and 1348, saint Pantaleon was chosen as saint patron. In 1835 as the church was too small, a new one was built. But from 1850, many cracks in the walls appeared. In 1874 and 1878, a new church was built with a larger nave. The roman bell tower was preserved. Behind the church, there are some archways from an old chapel Saint-Michel, which was an ossuary.
References: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.