The first Christian church was probably a wooden church. Of this church there is no trace, but the baptismal font in the Church today has probably belonged to this church. In the 1220s a new stone church of considerable size was built in round-headed Romanesque style and consisted of a nave with four pillars, chancel with two cross-arms and apse, an extension in the rear of the chancel where the altar was placed. A large tower in the west would be part of the building, but it never came to execution. The nave is left intact to this day. Lau church is the island’s largest country church. It is famous for its unique acoustics.
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.