The castle of the Rojas is located on the top of a hill near the town of Poza de la Sal. At the end of the 9th century Count Diego Rodríguez Porcelos repopulated Poza building the castle for the defense of the new territory. Like other castles of this time it may have been a simple keep surrounded by some walls.
In the 14th century Rodriguez de Rojas family rebuilt the current castle. It was occupied in 1808 by French troops and was a target of continuous attacks of Burgos garrisons until the end of the war.
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.