The first recorded mention of Holligen is in 1257, when it was owned by the Teutonic Knights commandry of Köniz. It is likely that there was a castle here to control the Bümpliz-Köniz road and administer the estates. However, very little is known of this building. The current castle was built around 1500 by the Bernese Schultheiss Wilhelm von Diesbach. It was built in the style of a typical Burgundian castle, with a square donjon of massive stone blocks with four towers at the corners. A residential hall with a staircase tower was added around 1575 for Peter von Graffenried.
A map by Thomas Schöpf from 1577 and a city plan from 1623/24 both show the castle surrounded by a ring wall with several small towers. Between the 1624 plan and 1667, the square castle was expanded with the construction and expansion of the residential hall to the west. In the 18th century the castle was renovated in the Baroque style. The facade and windows were redone in 1765.
Between 1991-1994 the castle was extensively renovated and repaired. Today it is owned by the Turmstiftung Schloss Holligen, a foundation that maintains the castle.
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.