Château du Guildo dates from the 11th century, when there was a fortified manor, probably made of wood. The stone castle was built in the 13th century in three phases. It was destroyed a century later and the new castle construction began in the late 1300s. Later it was restored as a living residence, but badly damaged in the late 1400s during the French-Breton War. The castle took part also to the Wars of Religion, when it was surrounded several times by Catholic League. This caused the final destruction Château du Guildo.References:
The eight towns in south-eastern Sicily, including Ragusa, were all rebuilt after 1693 on or beside towns existing at the time of the earthquake which took place in that year. They represent a considerable collective undertaking, successfully carried out at a high level of architectural and artistic achievement. Keeping within the late Baroque style of the day, they also depict distinctive innovations in town planning and urban building. Together with seven other cities in the Val di Noto, it is part of a UNESCO World Heritage Site.
In 1693 Ragusa was devastated by a huge earthquake, which killed some 5,000 inhabitants. Following this catastrophe the city was largely rebuilt, and many Baroque buildings from this time remain in the city. Most of the population moved to a new settlement in the former district of Patro, calling this new municipality 'Ragusa Superiore' (Upper Ragusa) and the ancient city 'Ragusa Inferiore' (Lower Ragusa). The two cities remained separated until 1926, when they were fused together to become a provincial capital in 1927.