Oslofjord

The Oslofjord (Norwegian: Oslofjorden, Urban East Norwegian: [ˈʊ̂ʂlʊˌfjuːɳ]; English: Oslo Fjord) is an inlet in southeastern Norway. The 120-kilometre (75 mi) fjord begins at the small village of Bonn in Frogn Municipality and stretching northwards to the city of Oslo, and then curving to the east and then south again. It then flows south to an imaginary line running between the Torbjørnskjær Lighthouse and Færder Lighthouse where it becomes part of the Skagerrak strait. The Skagerrak connects the North Sea and the Kattegat sea area, which leads to the Baltic Sea. The Oslofjord is not a fjord in the geological sense, but in the Norwegian language, the term fjord can refer to a wide range of waterways including inlets such as this one.

The bay is divided into the inner (indre) and outer (ytre) Oslofjord, separated by the 17 km (11 mi) long by 1 km (0.62 mi) wide Drøbak Sound. The innermost part is known as Bunnefjorden.

From 1624 until 1925 the name of the fjord was Christianiafjorden (or Kristianiafjorden), since Christiania was the name of the capital during this period (the Ch was changed to a K in 1877). Before that time, the Old Norse name of the fjord was Fold. The old name Fold led to the names of the counties of Vestfold ('the district west of Fold') and Østfold ('the district east of Fold') as well as the nearby district of Follo.

Each of the islands in the innermost part of the fjord has its own identity and distinguishing history. Among them are Hovedøya, Lindøya, Nakholmen, Bleikøya, Gressholmen, and Langøyene. These islands can be reached with the Oslo boats from Aker Brygge. Hovedøya is known for containing monastery ruins, Gressholmen for its rabbits, Nakholmen, Bleikøya, Lindøya for their cosy cabins at the water's edge, and finally Langøyene for its camping possibilities and beach.

The inner part of the Oslofjord has steep and forest covered hill slopes down towards the fjord.^{[citation needed]}

The Oslofjord has Norway's highest all year temperature: 7.5 °C (45.5 °F). February is the coldest month in the fjord with −1.3 °C (29.7 °F), while July normally reaches 17.2 °C (63.0 °F). The islands in the middle of the fjord are among Norway's warmest with high summer temperatures and moderate winters. The Oslofjord's relatively high temperatures enable various flora to flourish.^{[citation needed]}

The oldest settlements in the area surrounding the Oslofjord date from the Stone Age and the Bronze Age. It was here on the eastern and western shores that three of the best preserved Viking ships were unearthed, including the Gokstad ship. In historical times, this bay was known by the current name of the region, Viken ('the bay').

Oslofjord has been an important body of water strategically due to its proximity to the capital city of Oslo. During World War II, there were German installations at several points on its coastline. One installation in Hovedøya held 1,100 Wehrmacht soldiers and later women deemed Nazi collaborators at the National Internment Camp for Women in Hovedøya.