There are traces of Roman occupation including a fort, built in the late 300s AD, above the Alderneys only natural harbour. The Alderney Nunnery was probably located on the site of this one best preserved Roman forts in the British Isles.
The 26-foot tall Roman tower features 10-feet-thick walls. Built of stone and Roman concrete, many of the outer walls are still standing however only fragments remain of the tall tower that would have stood inside the walls, there is a similarity to Roman signal stations built in Yorkshire.
The British are believed to have refurbished the Roman fort in 1793, leveling off the tower walls in the process, according to Heritage Daily. When the German’s invaded the island it appears they inserted a Type 501 bunker neatly between the tower ruins, using the north and south internal walls effectively as shuttering to pour their concrete, according to Dr. Jason Monaghan, who is helping lead the excavation efforts.
The site is newly opened after a major make over. There are story boards, an information room, large WWII bunker and much, much more to explore on this amazing heritage site.
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.