Since the 18th century, the complex on the Siegberg has been known as the "Upper Castle". Until the 15th century, ownership of the castle was divided between the sovereigns of the time, the Archbishop of Cologne and the Counts of Nassau. From 1421, the Catholic counts of the House of Nassau-Siegen had sole rule over the town and castle of Siegen. The actual castle building in its present form dates mainly from the 16th-18th centuries. Since 1905, the Upper Castle has housed the collections of the Siegerland Museum of Art and Regional History. The centerpiece is the Rubens Hall, in which eight original paintings by the Siegen-born baroque painter are on permanent display. An important collection of portraits of Nassau sovereigns can be seen in the Oranier Hall. -> The Siegerland Museum is located inside the Upper Castle The Upper Castle and the Siegerland Museum are part of the city tour.