The Kula fortress of Kamerlengo (Fortress Sv. Marko) was built in the mid-15th century by Marin Radoj as part of an expansion of the Veriga Tower, built on the site in the late 14th century. As part of the defense system, the fortress was surrounded by a ditch filled with sand; inside the walls were a well and other structures for withstanding long sieges. St. Mark's Tower on the north end of the fortress was built shortly after the castle in typical Renaissance style and its roof once was ringed with guns at the ready to repel invaders. Kamerlengo began to deteriorate at the end of the 19th century and was renovated after World War II. Today the castle's interior courtyard is used as a summer stage and open-air cinema. Tourists can climb to the top of the tower and enjoy the view during the day and also at night when no movie is showing.