A church at the site of Sant'Agata was present by the 8th century, when the neighborhood was located outside the city walls, but after the 1184 fire destroyed the ancient church, it was reconstructed in the 15th-century in Gothic style. Destruction by fire of this church was somewhat paradoxical, since Saint Agatha was the saint invoked for protection against fires. Further modifications were completed along the centuries, leading to a pastiche of styles. The incomplete 14th-century facade has a Renaissance architecture facade, decorated with Baroque statuary.
Inside, the presbytery dates from the 15th century, the ceiling from the 16th century, the altars and fresco decoration from the 1680s, and the chapel of the Santissimo Sacramento is from the 18th century. The main altarpiece depicting Sant'Agata with Saints Peter, Paul, Lucia, Apollonia standing before the cross (1522) is a masterwork by Francesco Prata from Caravaggio.
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.