Cherven was one of the Second Bulgarian Empire's primary military, administrative, economic and cultural centres between the 12th and the 14th century. The town was a successor to an earlier Byzantine fortress of the 6th century, but the area has been inhabited since the arrival of the Thracians. Cherven was first mentioned in the 11th century in an Old Bulgarian apocryphal chronicle. It gained importance after 1235, when it became the seat of the medieval Bulgarian Orthodox Bishopric of Cherven.
During the second half of the 14th century, the stronghold's area exceeded 1 square kilometre and had intensive urban development, including a fortified inner city on vast rock ground in one of the Cherni Lom river's bends, and an outer city at the foot of the rocks and on the neighbouring hills. The town had a complex fortification system and was completely built up. Cherven grew to become a centre of craftsmanship in the 14th century, with iron extraction, ironworking, goldsmithing, construction and arts being well developed. The town was an important junction of roads from the Danube to the country's interior, which also made the town a key centre of trade.
Cherven was conquered by the Ottoman Turks in 1388 during the Bulgarian-Ottoman Wars, initially retaining its administrative functions but later declining in importance.
A large feudal palace with fortified walls reaching up to 3 metres wide, two well-preserved underground water supply passages, 13 churches, administrative and residential buildings, workshops and streets have been excavated. The three-storey tower, 12 metres high, from the 14th century has also been fully preserved and was even used as a model for the reconstruction of Baldwin's Tower in Tsarevets, Veliko Tarnovo, in 1930. The site has been a national archaeological reserve since 1965 and is a popular tourist attraction.
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.