The fort was built from 12th to the 14th century. It was raised by the family of Frankopan through several generations. The fort had several purposes, from guarding the city from the sea threats to the courtroom purpouse for which the square tower was intended. Height of the walls is 9 meters. 
Today the castle serves as a summer theater where variety of performances take place. Part of the walls is arranged for the tour, and with them you can see the beautiful vistas of the old town harbor and the Cathedral.