The designer of the 17th century defence fortifications is architect Erik Dahlberg. A total of seven bastions were built: Honor, Gloria, Victoria, Fama, Triumph, Fortuna, and Spes. There were interior rooms (cells) in some of the bastions. In the 1930s, tours were organized there. During the Second World War, the local residents used the cells as bomb shelters. Work has been started to dry our and light the bastions.