Viking ring fort and settlement, the Shetland Islands, Jarlshof, Scotland. It has been described as "one of the most remarkable archaeological sites ever excavated in the British Isles". It contains remains dating from 2500 BCE up to the century CE.
Viking Ring Fortress, Trelleborg/ trelleborg a collective name of circular forts in Denmark and southern Sweden. 5 are dated to the reign of herald Bluetooth first discovered example named after trellebrog near slagelse,denmark.