At the end of Via Rastello you come out into Piazza Cavour, once called Piazza Duomo, which overlooks the 16th-century Provincial Diet Building, now the seat of the Police Headquarters.

During the war, the square was the assembly and distribution point for units headed for the southern front. It was surrounded by mobile fences and fixed defenses positioned at the level of the birthplace of the painter Giuseppe Tominz. The buildings were not significantly damaged by the bombings because the square, thanks to the castle hill, was shielded from the fire of heavy Austrian artillery positioned on the edge of the Trnova plateau or on the Ajsovizza plain, which instead continuously bombarded the adjacent Piazza Sant'Antonio and the San Rocco district.