Bergenshus Fortress at the mouth of the Vågen harbour is where Bergen's history begins. The complex includes Håkonshallen — a great stone hall built around 1261 for the coronation of King Magnus Lagabøte — and Rosenkrantztårnet, a Renaissance tower built by the governor Erik Rosenkrantz in the 1560s on top of an older medieval structure. Both are open to visitors.
Håkonshallen is one of the finest surviving examples of medieval secular architecture in Norway. The tower gives good views over the harbour and out to the fjord. The open grounds around the fortress are worth wandering — there is a small café in summer — and the whole site is easily covered in a couple of hours alongside a walk along Bryggen.