The Benedictine Territorial Abbey of San Michele Arcangelo has been existed at least from 1078 and was probably built in the 5th century. The benedictine Abbey Church (12th century), dedicated to St. Michael, has a notable portal and a Norman-style bell tower with mullioned windows. The Norman lord Humphrey of Hauteville and his son Rudolph made large donations to the abbey. In 1484, after joining the Benedictine Congregation of St. Giustina from Padua, the abbey was enlarged and restored in Renaissance forms.
Afterwards it decayed due to numerous wars ravaging the country in those years. Renewed starting from 1590, it received a cylindrical cupola in 1650. The monks abandoned the abbey in 1784.
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.