Felsenburg castle was probably built in the 12th century for the Freiherr of Kien. The castle was built on a rocky spire above the road over the Gemmi pass into Valais. It was inherited, along with the rest of the Herrschaft of Frutigen, by the Freiherr of Wädenswil in 1290. The Freiherr of Turn acquired it from Wädenswil in 1312. It was mentioned in a record in 1339 as the castrum de Petra. It was again mentioned in 1368 as Stein, German for Stone. In 1400, Bern acquired the castle along with the rest of the Herrschaft. They abandoned Felsenburg and allowed it fall into ruin.
Currently, only the rectangular main tower and remnants of the outer walls are still standing.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.