It's often said that all of Genoa's historic center is on the list of UNESCO World Heritage Sites, but in truth the designation is more specific. It includes the city's “Strade Nuove,” or new streets, and the system of “Palazzi dei Rolli.”
The collection is made up of 42 palaces, all built in the 16th-18th centuries, which were listed on city's register – the rolls, or “rolli,” which later gave the system of palaces its name. Each time a dignitary was on a state visit to Genoa, he or she needed a place to stay that was worthy of his or her status. The palazzo that got the honor was chosen at random from the “rolli.”
The Palazzi dei Rolli were an early example of a city and its citizens forming a partnership of architectural design as well as cooperative urban planning. The palaces are unique, but they are of a design that suits the overall style. The Palazzi dei Rolli were added to UNESCO's list in 2006.
There were different categories of Palazzi dei Rolli, and most of the top tier palaces were on Via Garibaldi, Via Lomellini, and Via Balbi.