The construction of Sofia Albertina Church began in 1754 by the design of Carl Hårleman and it was inaugurated in 1788. It is named after the sister of Gustav III of Sweden. Sofia Albertina replaced the medieval church from the 1400s. The church has unusual design, because it has two towers but it's not a cathedral of bishop's seat.
The font dates from the 12th century. It was a used as a fountain in local family's garden until they noticed its value. Chandeliers were moved from the old church and they date from the 1600s.
References:Sigmaringen Castle was first mentioned in the year 1077 in the chronicles of Petershausen monastery. The oldest parts of the castle are concealed beneath the alterations made during the 17th and the 19th centuries. The secret of the earliest settlement built on this defendable rock will never be fully revealed: large-scale excavation work would be necessary, which the extensive land development renders impossible. Judging from the many Roman remains unearthed in the area around Sigmaringen, the 12th century keep known as the 'Roman Tower' could be traced back to a Roman predecessor.
The castle remains that have been preserved (gate, great hall and keep) date back to the Staufer period around 1200. The castle remains were integrated into subsequent buildings. The foundations of the castle buildings are to a large extent identical to the surrounding castle wall.
These remains give us a good idea of how the castle might have looked during the 12th century.