Fuentidueña de Tajo Castle is a large, irregular building standing on a hill which dominates the Town and the Tagus River. It is believed to have been built during the 12th century and has been extended and rebuilt later on in the 14th century. It is related to the Kings, Alfonso VI and Alfonso VIII.
It still has a wall and part of the cylindrical towers on the sides. The two sections composing it are separated by an interior moat. It is still possible to see the Homage Tower opposite the Town.This castle was the Headquarters of the Kingdom in the time of Da Urraca, wife of Alfonso I the Warrior; legend has it that at night she used to walk through the hidden corridors to visit the Moors.
The provincial Governor, Pedro Manrique, was imprisoned in this Castle by order of Juan II. Álvaro de Luna, Marquis of Villena, was also made prisoner for his discrepancies with the Order of Santiago; he later became the proprietor of the Castle.
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.