Skagerrak

Oslo is the capital and most populous city of Norway. It constitutes both a county and a municipality. The municipality of Oslo had a population of in 2025, while the city's greater urban area had a population of 1,110,887 in 2025, and the metropolitan area had an estimated population of in 2021.

Gothenburg ( ; ) is the second-largest city in Sweden, after the capital Stockholm, and the fifth-largest in the Nordic countries. Situated by the Kattegat on the west coast of Sweden, it is the gubernatorial seat of Västra Götaland County, with a population of approximately 600,000 in the city proper and about 1.1 million inhabitants in the metropolitan area.

Kristiansand is a city and municipality in Agder county, Norway. The city is the fifth-largest and the municipality is the sixth-largest in Norway, with a population of around 116,000 as of January 2020, following the incorporation of the municipalities of Søgne and Songdalen into the greater Kristiansand municipality. In addition to the city itself, Statistics Norway count four other densely populated areas in the municipality: Skålevik in Flekkerøy with a population of 3,526 in the Vågsbygd borough, Strai with a population of 1,636 in the Grim borough, Justvik with a population of 1,803 in t

The Skagerrak (; , , ) is a strait running between the North Jutlandic Island of Denmark, the east coast of Norway and the west coast of Sweden, connecting the North Sea and the Kattegat sea.

the northernmost part of Denmark and of Jutland

Strömstad is a locality and the seat of Strömstad Municipality, Västra Götaland County, Sweden with 6,288 inhabitants in 2010. For historical reasons, Strömstad is called a city despite its small population.

Lysekil () is a locality and the seat of Lysekil Municipality in Västra Götaland County, Sweden. It had about 7,600 inhabitants in 2018. Situated on the south tip of Stångenäs peninsula at the mouth of Gullmarn fjord, it has two nature reserves.

national park

elongated depression in the sea floor off the southern coast of Norway

Frier or Frierfjord is a fjord in Telemark county, Norway. The long fjord is located along the Skaggerak coast in the traditional district of Grenland and it forms the border with the municipalities of Bamble, Skien, and Porsgrunn. The fjord is actually an inner arm of the Langesundsfjord, and historically (well into the 1700s) this fjord was also known as the Langesundsfjord. The fjord stretches from the opening to Langesundsfjord in the south to the mouth of the Porsgrunn River in the north. The much smaller fjord of Gunneklevfjord opens into the Porsgrunn/Skien River and is separated from F