Aquis Querquennis is the ruins of a Roman military camp sit along a flooded section of a river. The construction of the barracks dates back to the reign of Vespasian, around the year 75, when it was likely used as a base from which to defend newly built roads connecting other, larger roads in this remote province.
The walls, arches and moat that form the foundations of this former Roman military camp can sometimes be found half submerged in the reservoir, depending on the amount of rain upriver and the status of the dam.
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.