The Arnarstapi shoreline is surrounded by the Hellnahraun lava field. Both were formed by an eruption 3,900 years ago. In 1979, these 143 acres were declared a nature reserve. The area is prime habitat for colonies of seabirds. The most common are kittiwakes. They glue their nests to the side of the cliffs and in gorges. Birdwatches will also recognize great black-backed gulls and Artic terns.
