It is not known with any certainty when Dill castle was built, but it is assumed that this happened in the 11th century, and that it might have been built on the ruins of an earlier Roman or Celtic complex.
At the complex's highest point, in the north, is the Oberburg (“upper castle”). Not much of the four-floor residential tower, whose sides measured 18 × 12 m, is left other than three outside walls; the east wall is missing. On the north wall's outer side is a garderobe. Parts of the barrel-vaulted cellar may still be visited. West of the upper castle, remnants of the girding wall have been unearthed. They exhibit a herringbone pattern in their construction.
On the area of the Niederburg (“lower castle” or “bailey”) to the east stand an Evangelical church, built on the spot where the castle chapel once stood, a wellhouse, which has been expanded into a holiday home, and a modern house.
Of the Vorburg (“forward castle” or perhaps “outer bailey”) to the west and south, only remnants of the foundations and outer wall can still be found. Part of the area is used as a garden.
The castle is in private ownership and normally cannot be visited. However, once or twice a year, there are guided tours. The times are published.
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.