Tvis Abbey is a former Cistercian abbey founded in 1163 by Prince Buris as a daughter house of Herrevad Abbey in Scania (now in Sweden). The abbey was dissolved during the Reformation, probably in 1547. The abbey church, which served as a parish church, was demolished, apparently in 1698, after which a replacement was set up in the west wing, but that too was demolished after the construction of a new parish church in 1887. Today there are no visible remains apart from the foundations.
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.