Situated on the market place in Siegen, the church of St. Nicholas was built in the 13th century and was once the parish church of the counts of Nassau.
The church of St. Nicholas is part of the City Tour.
The members of the protestant line of the House of Nassau-Siegen were interred here before the construction of the royal tomb. The hexagonal layout of the central building is unique in Germany and the building design is essentially Romanesque. The church's most precious possession is a baptismal font dating from the 16th century and made by Peruvian silversmiths which is still in use today. The coronet on the church steeple was bestowed on the parish in 1652 by Prince Johann Moritz of Siegen-Nassau. The gilt coronet has become the town's landmark. St. Nicholas' church has been the main parish church of the town since the Reformation, remaining protestant almost continuously throughout.