The 11th century wooden stronghold of Racibórz was rebuilt as a brick castle in the third quarter of the 13th century. Around 1290 a chapel was built in the castle with the significant dedication of Saint Thomas of Canterbury.
At present, its most valuable element is the castle chapel, due to its high artistic level called the pearl of Silesian gothic. Fortunately, the reconstructions from the seventeenth and nineteenth centuries did not manage to change its Gothic interior, and the 19th-century matroneum placed on the site of the medieval one, neatly imitates the likely appearance of the original. The gables, western entrance portal and vault in the western bay of the chapel have also been transformed. Next to it is the palace wing. Recently renovated it is a place of cultural and entertainment events and a small museum.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.