Castle Wild (Wildburg) lies southern behind the Castle Treis. It was built in the 13th or 14th century, probably as protection of the southern side of the castle Treis. In the fifties it was restored and made fit to live in. Back then, the northern situated, almost square, donjon was repaired and received a new roof. The great hall and other outbuildings were also rebuilt. Other buildings and the circular wall are just ruins. Wildburg is private property so you can visit it only from the outside.
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.