The Rosenkrantz Tower, also known as the Bergenhus Fortress, is a medieval castle located in Bergen, Norway. It is one of the oldest and most important landmarks in the city, and has played a significant role in Norwegian history for over 700 years. The tower is named after its most famous owner, Erik Rosenkrantz, who lived there during the 16th century.

Built in the 1270s by King Magnus VI of Norway, the Rosenkrantz Tower was originally part of the Bergenhus Fortress, which served as the royal residence and administrative center for western Norway. Over the centuries, the fortress underwent several additions and renovations, with the tower being expanded and fortified in the 16th and 17th centuries.

Today, the Rosenkrantz Tower is open to the public as a museum, showcasing the history of the Bergenhus Fortress and its role in Norwegian military and political history. Visitors can climb to the top of the tower for panoramic views of Bergen and the surrounding area, and explore the various rooms and exhibits inside. The museum contains a range of artifacts and exhibits, including medieval weapons and armor, historical documents, and artwork.

The Rosenkrantz Tower is a popular tourist attraction in Bergen and a significant part of Norway's cultural heritage.