The Lubwartturm observation tower is the keep of the former castle of the dukes of Saxony in Liebenwerda. When the last duke of the Ascanian dynasty died in 1422, the castle, located on the Schwarze Elster River, became property of the Wettin dynasty, who established the administration of the Liebenwerda office here. Martin Luther met the papal envoy Karl von Miltitz at the castle in 1519. The Mitteldeutsches Marionettentheatermuseum, the Central German puppet theatre museum, is located in a former municipal building. It has an extensive collection of puppets.