Casteldoria Castle was built around the 12th century by the Genoese Doria family, and passed from the Genoese dominion to the Aragonese, then to the Arborea Giudicato and lastly to the Malaspina family.
Only a few ruins remain of the fortress: parts of the walls, the remains of a chapel and a large cistern that was probably used to collect and store water. The famous tower, on the other hand, is well-preserved, and is an important part of the castle, built in large, rectangular granite blocks set in mortar. Twenty metres high, it has a pentagonal layout with the entrance on the north-eastern side. On the same side are two large, non-aligned openings, and a large window on the opposite side on the first floor. Inside, the castle has three wooden floors with a tiled roof and walkway. The last floor was created from what was originally a mezzanine floor before a terrace.
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.