The Synagogue of Santa María la Blanca was erected in 1180, according to an inscription on a beam, it is disputably considered the oldest synagogue building in Europe still standing. It is now owned and preserved by the Catholic Church.
Its stylistic and cultural classification is unique among surviving buildings as it was constructed under the Christian Kingdom of Castile by Islamic architects for Jewish use. It is considered a symbol of the cooperation that existed among the three cultures that populated the Iberian Peninsula during the Middle Ages.
The synagogue is a Mudéjar construction, created by Moorish architects for non-Islamic purposes. But it can also be considered one of the finest example of Almohad architecture because of its construction elements and style. The plain white interior walls as well as the use of brick and of pillars instead of columns are characteristics of Almohad architecture. There are also nuances in its architectural classification, because although it was constructed as a synagogue, its hypostyle room and the lack of a women's gallery make it closer in character to a mosque. Though it does not have a women's gallery today, an early twentieth century architect suggested that it did at one time have a one.
The synagogue was turned into a church in 1405 or 1411, but without any major renovations. It took at that time the name of Santa María la Blanca (Saint Mary the White) and today it is most commonly known by this name.
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.