The Parish Church of St. Gallus and Ulrich was built in 1734-1738 by Johann Georg Fischer through the conversion of a Gothic church predecessor. It was extensively renovated between 1974 and 1980. The church contains a Madonna of 1623 (attributed to Hans Zürn the Elder), a baroque pulpit of divination Johann Wilhelm (1745) and numerous tombs of the 16th and 17th century. The church also has a valuable treasure of silver (1741-1755) from the workshop of the Augsburg silversmith Franz Christoph Mäderl.
The church also contains a purported relic of Saint Clemens that is in fact an example of a so-called catacomb saint, a corpse that has been taken from the Roman Catacombs, decorated, given a fictitious name, and presented as the relic of a Roman Catholic saint.
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.