Trevejo Castle origin dates back to before the 12th century when a Muslim fortress stood in its place, serving as the basis for its construction in the 15th century. The original fortress was conquered by Alfonso VII of León, who handed it over to the Order of the Temple. In 1184, by order of King Fernando II of León, it passed into the hands of the Order of St. John of Jerusalem. Two years later, the same monarch decided to give it to the Order of Santiago. Over the course of history, it also came to belong to the Order of Alcántara.
During the French invasion of the peninsula, the castle was destroyed to prevent Spanish guerrillas from taking refuge in it.
Today, the homage tower and a large part of the wall still resist the passage of time. At the foot of the castle, there are a series of anthropomorphic stone tombs, allegedly containing the remains of some of the warrior monks who were initially owners 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.