Abusina or Abusena was a Roman castra (military outpost), and later of town, of the Roman Province of Raetia.
It was at Eining near Abensberg, on the Upper German- Raetian Limes , which at this point was the Danube River. Abusina stood near to the eastern termination of the high road which ran from the Roman military station Vindonissa on the Aar to the Danube.
In the 2nd century the fort was occupied by the Cohors IV Tungrorum with about 1,000 men. By the later Roman Empire, archaeology and the Notitia Dignitatum suggest the site was occupied by Cohors III Brittonum with only 50 men.
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.