Orivirran saarto is a ruin of the 16th century fortress. It was built probably in 1540's, because in 1546 Russians complained about Swedish cutting forest and gathering stones in Orivirta. There were probably a main castle, outer fortication, watchtower and dock. During 16th century it was garrisoned by 400-600 men and 5-10 cannons.
In 1592 Russian cossacks destroyed the fortress. In a fight over 200 men were died and Swedish lost a ship and several cannons. After defeat Orivirran saarto was changed to guard place and fortified again during the Russo-Swedish War in 1656–1658.
Nowadays there remains some ruins of the fort restored by the Finnish National Board of Antiquities. There's also a memorial erected in 1965.
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.