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:House of the Blackheads (Melngalvju nams) is a building situated in the old town of Riga. The original building was erected during the first third of the 14th century for the Brotherhood of Blackheads, a guild for unmarried German merchants in Riga. Major works were done in the years 1580 and 1886, adding most of the ornaments.
The structure was bombed to a ruin by the Germans June 28, 1941 and the remains demolished by the Soviets in 1948. The current reconstruction was erected from 1995 to 1999. Today the House of Blackheads serves as a museum and sometimes concert hall.