Currently the main administrative wing of the University of Osnabruck. The original building was a 17th century palce built for the Bishop Ernst August and his wife. The building was almost completely destroyed by raids during World War II. Subsequently, the interiors were rebuilt. The castle has a somewhat dark history during the Nazi regime, the basement of one wing functioned as a Gestapo detention center, where a plaque to the victims has been put up. The Schloss Osnabrück is thus an architectural reminder of the history of the city, through it's various phases over the years.