The Ipf is a mostly treeless mountain (668 metres)with a prehistoric hill fort on its top. The fort is situated on an isolated hill, with a flattened summit surrounded by a stone wall, ditch and large counterscarp (outer bank). The overall diameter is about 180 metres. There are also extensive ramparts traversing the slopes to protect a large enclosed area and entranceway. There is evidence of occupation from the Bronze Age through the Iron Age to the early Celtic La Tene period, a span of almost a thousand years (1200 BC - 300 BC).
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.