The origins of the Castillo de la Yedra could be Muslims, possibly from the Almohad era. During the 11th and 12th centuries, the first fortress was built, but the current appearance was built by Christians during the 13th and 14th centuries and during the papacy of don Pedro Tenorio. The alcázar was built by the archbishops of Toledo at the end of the 14th century. There is a keep and a small parade ground that surround the alcazar.
Its construction was designed exclusively for military use as a palace of a feudal lord or small court of medieval monarch. That is why its architecture is sober, although compensated by the beauty of the topography of its location and the surrounding landscape.
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.