Orivirran saarto is a ruin of the 16th century fortress. It was built probably in 1540's, because in 1546 Russians complained about Swedish cutting forest and gathering stones in Orivirta. There were probably a main castle, outer fortication, watchtower and dock. During 16th century it was garrisoned by 400-600 men and 5-10 cannons.
In 1592 Russian cossacks destroyed the fortress. In a fight over 200 men were died and Swedish lost a ship and several cannons. After defeat Orivirran saarto was changed to guard place and fortified again during the Russo-Swedish War in 1656–1658.
Nowadays there remains some ruins of the fort restored by the Finnish National Board of Antiquities. There's also a memorial erected in 1965.
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.