Begun as a three-aisle hall church at about the same time as the town Ribnitz was founded, the oldest pre-Romanesque parts of the St. Mary's Church are located in the western outer wall of the building. Pilister corner strips, a rounded frieze and lanset windows are amongst other remanents of this first church.
In the 14th century, the church was enlarged by the addition of two bays, and decorated by the addition of peaked arch portals in the north of south of these. After a 1455 fire, the building was rebuilt with a pentagonal choir bay and a massive ornamental helm on the top of the spire. The Great fire of 1759 destroyed this ornamental helm, as well as the building's vaulting and medieval interior. Under instruction of the court masterbuilder Johann Jachim Busch of Ludwigsluster, the tower's roof and its interior was rebuilt in a Gothic style.
The centre aisle of the church was distinguished from this time on by a semi-circular barrel-shaped timber supports, the side-aisles by a flat wooden roof. Busch envisaged a pulpit alter, and after the pulpit was relocated into the church nave, the alter was completed with the addition of the Ludwigluster court painter J.H. Surlandt; the image is a copy of Annibale Carraci's 'The Burial of Christ'. The church's northern and southern side-chapels were never restored due to insufficient funds, with the foundations also removed. Between 1841 and 1843, Georg Adolph Demmler oversaw the addition of a latern to the of a Baroque-style tower crown, heighening the tower, which still offers a sightseeing platform to visitors. In the 1970s, the church was threatened by structural damage, losing once more much of its interior: the 1883 organ, built by Friese of Schwerin, was removed. After 1980, the church was renovated, the interior again altered and a winter church on the site added.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.