The east wing of Gram Castle was built in the beginning of the 16th century. The builder is unknown, but was probably one of the Reventlow family, who owned Gram from about the middle of the 15th century until 1560. The south wing was built by the Commander Hans Schack (1609 - 1676) a few years after he bought the manor in 1664. The west wing of the manor was built 1752 by Countess Anna Sophie Schack (1689 - 1760). Today it is a conference center.
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.