Raet National Park covers the coastline and seabed east of Arendal, protecting a stretch of the Skagerrak shore that includes skerries, archipelago islands, and underwater terrain of exceptional ecological interest. The park is Norway's first marine national park and one of the more unusual protected areas in Scandinavia.
The marine environment includes cold-water coral reefs, kelp forests, and diverse fish communities. Above water, the islands and headlands of the park are accessible by kayak or small boat, and the park authority runs guided snorkelling and diving excursions from Arendal in summer. The coastal scenery — granite skerries, pine-covered islands, clear water — is quintessential southern Norway at its best.