On Vatnsnes peninsula
Borgarvirki is a 10-15 metre high ridge of columnar rock. This phenomenon is a volcanic plug, and there is speculation as to whether it was, in ancient times, a district fortress and even, perhaps, a battleground.
From Borgarvirki there is a wide panoramic view over a large part of the region and a viewfinder is in place to help locate some of the important landmarks.
This is truly a unique natural phenomenon, but one which has also seen some improvements by the hand of man in bygone days.