Steyregg Castle dates back to the late 11th century (a similar structure, most likely made from wood, was there already before the turn of the last millenium). After the castle had been hit by two fires in the 18th century the original architecture remained largely untouched afterwards.
The castle was carefully renovated and extended in 2004 and its splendid rooms can be rented for private events. Especially beautiful is the castle chapel (late 13th – early 14th century) with its magnificent gothic frescoes from the 14th century (redone in baroque style in 1680). Parts of Steyregg's former city walls are still in good condition.
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.