They were the work of local master builders, which, in lengthy and persistent labour, at first constructed low defensive fortifications, and later, in their traditional manner, erected high walls with the characteristic battlements, made of cut quarrystone. The walls were renewed repeatedly. An older square tower stands next to the former city gate, while the round towers stem from the Renaissance. The latest restoration works on wall fragments lining Prolaz Venecija and the seashore side of the Brolo Park were carried out in 2004/05.