Marienberg Fortress is a historic castle located in Würzburg, Germany. It was built in the 13th century and served as the residence of the Prince-Bishops of Würzburg. The fortress is known for its impressive architecture and strategic position overlooking the city and the Main River. The fortress features several notable structures, including the St. Mary’s Chapel and the Main Guard. Visitors can explore its extensive grounds, which offer panoramic views of Würzburg and the surrounding landscape. Today, Marienberg Fortress is a popular tourist destination and houses the Würzburg Residence Museum.