The Salvador church was erected on the remains of the Ibn Adabba, the Great Mosque of Muslim Seville (9th century). This religious temple, as well as its surroundings, had great importance in the daily life of the people, which is why when the Christians conquered Seville, they allowed it to be used as a mosque in the beginning, but in 1340, it was converted into the parish of Salvador.
In addition, it was agreed to maintain the ostentatious rank of the second temple of the city; for it was granted a collegiate character. Thus, this building would continue to be used religiously until 1671, when the passage of time left it strongly deteriorated. Its construction as we see it today began in 1674 with the architect Esteban García. Work ended in 1712 under the architect Leonardo de Figueroa.References:
The Petersberg Citadel is one of the largest extant early-modern citadels in Europe and covers the whole north-western part of the Erfurt city centre. It was built after 1665 on Petersberg hill and was in military use until 1963. It dates from a time when Erfurt was ruled by the Electors of Mainz and is a unique example of the European style of fortress construction. Beneath the citadel is an underground maze of passageways that can be visited on guided tours organised by Erfurt Tourist Office.
The citadel was originally built on the site of a medieval Benedictine Monastery and the earliest parts of the complex date from the 12th century. Erfurt has also been ruled by Sweden, Prussia, Napoleon, the German Empire, the Nazis, and post-World War II Soviet occupying forces, and it was part of the German Democratic Republic (East Germany). All of these regimes used Petersberg Citadel and had an influence on its development. The baroque fortress was in military use until 1963. Since German reunification in 1990, the citadel has undergone significant restoration and it is now open to the public as a historic site.