Gåseborg was an magnificient ancient hill fort built in the Iron Age, about 1500 years ago. It was built of stone without any masonry. According the archaeological excavations the fort has been also a temporary residence. For example remains of golden artefacts have been found from the site.
References:These are great photos, thanks for uploading. I grew up in Viksjo and used to play on this mountaintop. Would love to visit today and take some photos, but I live in the US now. Thanks!
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.