Just north of the ridge summit of Cefn Bryn, there is a neolithic burial ground, known as 'Arthur's Stone' (Maen Ceti). Its name comes from a legend that the ancient British King Arthur threw a large stone from Llanelli which landed on this spot.
It is believed that during the Bronze Age Cefn Bryn was used extensively for ceremonies and rituals. Beneath the bracken on the hill over sixty cairns have been discovered. Most of these are likely to be no more than collections of stones cleared by local farmers; but just north-west of Arthur's Stone three prominent cairns have been excavated that prove their ancient role - the largest being Great Cairn, a circular heap of stones above a central grave.
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.