Malmö’s first castle was built in 1434. In 1537, King Christian III of Denmark constructed this Renaissance fortress called Malmöhus. The citadel served Danish kings until Sweden’s independence in 1658. Then, it became a defense against the Danes. From 1828 to 1909 it was a prison. Since 1937, Malmöhus has been the home of the Malmö Museum except for a short period in 1945 when it sheltered survivors of German concentration camps. The museum has a collection of art, city history, natural history and maritime exhibits.