The Abbey Church of Notre-Dame, sometimes referred to as 'Montivilliers Abbey' dates back to 684, although it was destroyed a Viking raid in 850, and rebuilt as a church in both the Romanesque and Gothic styles. It fell into decline by the late 1700's. Its decline went up to the French revolution at the end of the 18th century when it was closed and sold. Fortunately the abbey was not destroyed and was later bought back by the city of Montivilliers. An ambitious restoration program which was completed in 2000 gave back to the abbey its splendor.
Besides the church, it now houses exhibition rooms and the cloister has regained its elegance. The plan of the abbey is a traditional one: western building mass with two towers, large un-vaulted nave, projecting transept, lantern tower and gradated tower. The older parts are located in the choir and in the base of the western mass which dates from the end of the 11th century.From the renovated refectory to the rebuilt cloisters, and from the chapter house to the dormitory, as part of a moving museum exhibit that vibrantly evokes the nuns' lives, the abbey's history and its architecture.
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.