Sicily has been colonized by the Greeks, Romans, Byzantines, Ostrogoths, Muslims, Normans, Hohenstaufen, Angevins and Aragonese. Later, it became a province of the Spanish Empire and then was part of the Bourbon Kingdom of the Two Sicilies, and then the Kingdom of Italy in 1860. The extraordinary diversity of architecture on the island is a result of this rich sequence of disparate cultures.
After the massive destruction caused by the earthquake in 1693, the Sicilian Baroque emerged during a major surge of a rebuilding of the towns and cities of southeastern Sicily, particularly the Val di Noto, in late Baroque style. Described as “the culmination and final flowering of Baroque art in Europe,” the Sicilian Baroque keeps typical Baroque curves but also contains unique freedom of architectural design which shows itself the most through Grotesque masks, concave or convex façades, balconies and external staircases

Baroque Noto was built from scratch 9 kilometers to the south of Noto Antica after the destruction by the 1693 earthquake. It exhibits an outstanding example of town planning on a grid system. The artistic inspirations of three architects, Rosario Gagliardi, Vincenzo Sinatra and Paolo Labisi, dominate the architectural history of Baroque Noto and form a masterpiece of architectural unity.

Late Baroque Towns of the Val di Noto (Noto, Caltagirone, Militello Val di Catania, Catania, Modica, Palazzolo, Ragusa and Scicli) were listed as UNESCO World Heritage in 2002 for not only representing a high level of architectural and artistic achievement but also exhibiting distinctive innovations in town planning and urban building.
Here are the criteria of UNESCO for inscribing the Late Baroque Towns of the Val di Noto on the World Herritage List in 2002

The Late Baroque Towns of the Val di Noto in south-eastern Sicily provide outstanding testimony to the exuberant genius of late Baroque art and architecture.
The Late Baroque towns of the Val di Noto represent the culmination and final flowering of Baroque art in Europe.
The exceptional quality of the late Baroque art and architecture in the Val di Noto lies in its geographical and chronological homogeneity, and is the result of the 1693 earthquake in this region.
The eight Late Baroque Towns of the Val di Noto in south-eastern Sicily are characteristic of the settlement pattern and urban form of this region, are permanently at risk from earthquakes and eruptions of Mount Etna. “