The Fortress San João Baptista da Foz do Douro was built in the late sixteenth century to better protect the coast and the mouth of the Douro River. The monument is occupied today by the Regional Delegation of the Institute of National Defense. It is a fine example of military architecture. The original basic structure was enhanced with more recent bulwarks. The Lawn Tennis Club da Foz is located at the foot of the Fort.
Visits to the Fort are free on weekdays between 9h and 17h30. There are no official guided tours, but if you are part of a large group, it is advisable to contact the Fort ahead of time to ensure that the visit does not disturb its activities.
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.