The Monastery of Royal Saint Mary of Iranzu is a Roman Catholic monastery located in Abárzuza, Navarre. It was founded by Pedro de Artajona in the late 12th century, being Artajona's place of burial upon his death in 1193. The Cistercian Order had a large part in its building throughout the 12th century.
It was dissolved in 1839 and confiscated by the State. It was abandoned and became ruinous until 1942, when the Provincial Government of Navarre refurbished it. One year after, a Theatine Fathers community was established there. The Cistercian-style church was built during 12th century. The cloister is partly Cistercian (12th century) and partly Gothic (13-14th centuries). Additional minor Renaissance parts were added during 17th century.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.