Kalø Castle was founded in 1313 by the Danish king Erik Menved in order to establish a stronghold in northern Jutland to counter the ongoing rebellions by the local nobility and peasants against the crown. The castle was successful and from the 15th century and onwards the castle had a more peaceful role as the local administrative center. King Christian II held the future Swedish king Gustav Vasa captive at Kalø during 1518-1519, until he escaped.
When king Frederick III converted the elective monarchy into an absolute monarchy by the revolution of 1660 in Denmark, the castle lost its function. In 1661, Frederick III gave Kalø to Ulrik Frederik Gyldenløve, who in the following year (1662), tore down the now abandoned castle. The material was used to build his private palace in Copenhagen, now called the Charlottenborg Palace. Today the castle ruin is owned by the Danish State.
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.