The Nikolaikirche dates back to the first half of the 11th century and is just 29 meters long. The nave of the church has a large Romanesque arch on the west side. A round apse with a diameter of 6.8 meters adjoins the choir. A few slender pointed arches indicate that some structural changes were made during the Gothic period. Originally, the church also had a tower on the west side, but it was demolished when stones were needed to rebuild the town church of St. Peter and Paul. Inside, a freestanding sacrament house from around 1500 deserves special attention. It is a rarity of its kind in Thuringia and Saxony. In addition to this sacrament house, the upper part of a baptismal font from the transition period from Romanesque to Gothic has also been preserved. The octagonal cup shape already corresponds to the Gothic period, while the main cornice with the round arch frieze is Romanesque.

St. Nikolai was once the church of the first settlement at the foot of the castle and on the banks of the White Lake. It retained its parish rights until 1539 and was then almost forgotten due to misuse. It was only rediscovered in the 1920s and restored in 1934. It is surrounded by spacious church grounds, which are bordered by a wall with a late Gothic gate.