The first enclosure-type brick castle in Senieji Trakai was built by Grand Duke Gediminas, who transferred the capital of Lithuania from Kernavė to Trakai (today's Senieji Trakai) before 1321. The wedding of Grand Duke Kęstutis and Birutė was held there and it was the birthplace of the Grand Duke Vytautas in 1350.
The castle in Senieji Trakai was destroyed by the Teutonic Order in 1391, subsequently abandoned and never rebuilt as a new castle had been erected in Trakai by Kęstutis. The ruins of the castle were granted to Benedictian monks by Vytautas in 1405. It is presumed that the present monastery building, dating from the 15th century, holds the remains of Gediminas castle.
Archaeological research on the hillfort mound was carried out in 1996–1997. The findings confirmed the existence of a former rectangular masonry castle wall, which had surrounded the hill. It is supposed that the residential buildings had occupied the area near the church and the churchyard.
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.