Kosterhavets National Park is Sweden’s first marine national park, running from Strömstad in the north to Grebbestad in the south. It covers coastal and marine environments with plant and animal life both above and below the water. The park is described as a year-round destination.

Visitors can hike by the sea, paddle, dive, swim or snorkel. Other listed outdoor activities include cycling, birdwatching and fishing. Boat trips and seal safaris are additional ways to experience the park. These activities are available along the mainland coast and in the outer archipelago.

The Koster Islands, Saltö and Västra Rossö-Kockholmen are named as archipelago areas to visit. For an introduction to the national park, Visit Sweden recommends Naturum Kosterhavet at Ekenäs on Sydkoster as a good first contact. The park is described as a recreation area for outdoor life and a place for nature experiences in every season.