The fortified town of Rello still maintains the original defensive walls and castle that were used as protection against civilisations that came from the south following the Douro River. It is the best-preserved walled enclosure in the province.
You can go inside through either one of the two gates located on the sides of the castle. The castle is protected by a fortified enclosure with circular and quadrangular towers that have elbow openings. The upper part of the towers are crowned with 15th-century machicolations and you can still see some remains of the keep, a water pool and a wall of the gate that separated the castle from the rest of the town.
In the outer enclosure, there are still gunboats in the lower section that were used for artillery.
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.