If you were to build a perfect fortification and place it in a strategically relevant place, it might still not match the rock formation Borgarvirki. Located approximately 180 meters above sea level with a magnificent view in every direction, Borgarvirki has a strategically unparallel placement. Although it looks very much like a man-made fortification, it is actually a natural formation. Mostly referred to as a defense shelter, it is also a great place for viewing the surrounding area. There is a good parking lot by Borgarvirki and only a short, interesting walk to the entrance. It is also easy to walk up to the brim and almost the whole circle on top.
It is definitely interesting as a natural wonder of basalt columns.
Borgarvirki or The Rocky Hill Fortification, as it could be translated into English, is a rocky hill made of basalt columns. The rocky hill is 10 to 15 meters high with a hollow in the middle, surrounded by 6-meter walls, and has only one entrance to the east. It is not big and has probably never housed a large group of armed men. Although most of what happened from settlement to medieval times is quite well documented in Iceland in the Sagas, there is no mention of any battle at Borgarvirki. There is one story, though, about Víga Barði and his flock of local farmers using it as a defense against a flock of thugs from the western part of Iceland. For the attackers, it was impossible to enter Borgarvirki, so they decided to wait until huger forced Víga Barði and his people out of the fortress. But when they started to throw food from the inside of Borgarvirki to the attackers after days of waiting, the thugs from the west gave up, thinking that Víga Barði and his people had food that would sustain them for weeks or months. So, the idea that it was at some point a fortification is only a speculation. One of the reasons why stories about it being a fortification have developed is because its entrance is a stonewall that was built hundreds of years ago. But as a natural wonder, Borgarvirki is interesting to visit and has a noteworthy geological formation.
Moreover, it is easily accessible from the Ring Road in Iceland.
Borgarvirki is located only 10 kilometers from the Ring Road or Road 1 in Iceland on a turn to the north on Road 716. It is also only a short walk from the parking lot to the top of Borgarvirki. There you can enjoy both the magnificent view over Vatnsdalur to the south and Vatnsnes to the north. You will also get to see the magnificent basalt column formation!