Burg Altena is a historic castle located in the town of Altena, Germany. Built in the 12th century, it sits on a hill overlooking the Lenne River. The castle is known for its impressive architecture and well-preserved structures, making it a popular tourist destination. The castle has served various purposes throughout its history, including as a fortress and residence for noble families. Today, it houses a museum that showcases the history of the castle and the region, offering visitors a glimpse into medieval life and the significance of the Sauerland area.