The first wooden Morag castle was built around 1280 by Teutonic Knights. It was rebuilt as a brick castle between 1331 and 1384. It was surrounded by a deep moat. In 1414 the castle moved temporarily to the possession of Poland army. The castle was abandoned later and the tower was demolished in 1616. Today ruins and a later Renaissance manor remain.
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.