Probably built in 837 by Orso I, the Monte Sant'Angelo Castle has bastions of different ages. The most ancient part, called Torre dei Giganti ('Giants' Tower') is a pentagonal tower 18 m-high, with walls 3.7 m thick. The first documents on its history dates back to 979; later, it was the residence of Rainulf I of Aversa and the Robert Guiscard, who built the Norman Tower and the Treasure Hall.
Emperor Frederick II restored the construction to use it as residence for his mistress Bianca Lancia, while under the Angevines it was used mainly as prison. Later, from 1464 to 1485, the fortress was the residence of the exiled Albanian condottiero Skanderbeg. The castle was largely rebuilt in the late 15th century by Ferdinand I. According to a legend, the castle is currently home to the ghost of Bianca Lancia, whose sighs can be heard especially in the winter time. Today the castle is used for exhibitions.
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.