Santo Stefano d'Aveto Castle controlled the roads from the Apennines to Emilia. It was probably built int the 12th century, first time documented in 1164.
The castle that presents itself now is an interesting pentagonal structure with ramparts on four of the five perimetral corners. In ancient times the arms square could be reached, an area onto which the different rooms on the ground floor open, using drawbridges that were easy to lift in case of attacks.
References:Visby Cathedral (also known as St. Mary’s Church) is the only survived medieval church in Visby. It was originally built for German merchants and inaugurated in 1225. Around the year 1350 the church was enlarged and converted into a basilica. The two-storey magazine was also added then above the nave as a warehouse for merchants.
Following the Reformation, the church was transformed into a parish church for the town of Visby. All other churches were abandoned. Shortly after the Reformation, in 1572, Gotland was made into its own Diocese, and the church designated its cathedral.
There is not much left of the original interior. The font is made of local red marble in the 13th century. The pulpit was made in Lübeck in 1684. There are 400 graves under the church floor.