The Vastseliina Castle was a castle of the Livonian Order, Bishopric of Dorpat. It was constructed in 1342 by the Landmeister Burkhard von Dreileben as part of the border fortifications of Old Livonia against Novgorod, Pskov and later Moscow. In the Middle Ages, Vastseliina Castle was well known in the Catholic world as a popular destination for pilgrims. They worshipped the holy cross in the castle chapel and a visit to the chapel gave them sanctification for 40 days – it was first validated by Pope Innocentius VI in 1354.
The castle met its end during the Great Northern War when it was demolished by Russian troops (1702). Today the ruins are open to the public.
Reference: Wikipedia, VisitEstonia
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.