Plainburg Castle - the family seat of the Counts of Plain and a symbol of Großgmain - is one of Austria's oldest castle ruins and offers a magnificent view over Großgmain and the surrounding mountains. All that remains of the original structure are the outside walls, with a thickness of 1.4m and standing to a height of over 5m. A short climb rewards the visitor with the opportunity to stop and rest awhile at the viewing platform overlooking Großgmain. Before it became the seat of the Counts of Plain, the mountain was a Celtic burial ground during the late Bronze Age around 1200 BC. Some time later, in about 1100 AD, Count Werigand of Plain built Plainburg Castle.
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.