Borgarvirki is a volcanic plug in North Iceland that has been used as a fortress throughout history. Standing at 177 meters above sea level, this columnar rock formation was fortified by early Vikings and offers stunning views of the surrounding landscape. It is believed to have been used by the clans of the Húna district during the Icelandic civil war. Visitors can explore the ruins of human habitations on site and enjoy the nearby attractions on the Vatnsnes Peninsula, such as Hvítserkur rock formation and seal colonies.