The location of Sønderborg Castle is quite magnificent as it sits proudly at the entrance to to the town. The museum focuses on almost 800 years of the dramatic history of Sønderjylland and Schleswig. The castle was built as a fortress in the 12th Century. King Christian II was imprisoned here from 1532 to 1549. Queen Dorothea’s chapel is one of the unspoiled royal chapels from the Reformation. See also the exhibitions on the War of 1864, the First World War and the reunification of Denmark in 1920.