St. Mary's Church (Marienkirche) is a large Lutheran church built some time before 1298. It is architecturally Gothic, an example of the brick gothic style prevalent in northern Germany. Between 1625 and 1647, it was the tallest building in the world at 151 metres tall.
The bell tower collapsed in 1382, and was rebuilt by 1478. In 1495, the steeple tower blew down during a severe storm, and was then rebuilt taller. This was subsequently struck by lightning in 1647, and burned down, and was rebuilt as a baroque dome, which, completed in 1708, can be seen today. The tower is currently 104 metres tall.
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.