Tvrđa (Citadel) is the old town of the city of Osijek. It is the best-preserved and largest ensemble of Baroque buildings in Croatia and consists of a Habsburg star fort built on the right bank of the River Drava. Tvrđa has been described by the World Monuments Fund as 'a unique example of an eighteenth-century baroque military, administrative, and commercial urban center'.
The star fort was constructed in the immediate vicinity of medieval Osijek after the defeat of the Ottoman forces in 1687, due to Osijek's strategic importance. Constructed starting in 1712 to plans by Mathias von Kaiserfeld and then Maximilian Gosseau de Henef, all five planned bastions and two gates were complete by 1715. By 1735, the inner town was finished and three northern bastions had been added. When complete, it was the largest and most advanced Habsburg fortress on the border with the Ottoman Empire, consisting of eight bastions and featuring armories, depots, a garrison headquarters, military court, construction office, a garrison physician, guardhouse, officers' apartments, a military hospital and seven barracks. The completed fort was entirely surrounded with walls and palisades and had four main gates at each side. Tvrđa had street lights by 1717 and was the site of the first public water supply in Croatia, opened in 1751.
Tvrđa's military importance decreased after the Berlin Congress of 1878, with the increasing stability of the surrounding region. Most of the fort walls and fortifications were destroyed in the 1920s due to the obstacle they presented to the development of Osijek. While the fortifications have largely been removed, the fort's interior core remains intact and is now home to churches, museums, schools and other public buildings, as well as numerous bars and restaurants. Of the fortification system, only the northern side of the walls now remain intact, as well as parts of the first and eighth bastions along with the northern gate known as the 'water gate' (vodena vrata). Tvrđa sustained significant damage during the Croatian War of Independence during the 1990s and was featured on the 1996 World Monuments Watch List of Most Endangered Sites. It now features on Croatia's tentative list for consideration as a nominee for a World Heritage Site.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.