Hellisskógur is a small forest just outside of the town of Selfoss. In Hellisskógur are roads, walking paths around the area, and benches so visitors can relax and enjoy the site.
The cave in Hellisskógur forest was formed during a latter glacial period by sea erosion. Sea levels have been higher than now several times, and signs of sea erosion can be seen on more cliffs in the area, made of around 0, 7 – 3, 1 million-year-old basalt. The cave was previously used to store hay in the back and as a sheepcote in the front.
It was once believed that the cave was haunted by a ghost wearing a blue scarf. The story tells of a young man who was broken hearted and hung himself in the cave using a long blue scarf.