The Oslofjord is a long channel off the Skagerrak Strait, which leads from the North Sea to the Baltic via the Kattegat. It is not a fjord in the geologic sense, being more accurately a bay leading to Norway’s capital. It is dotted with islands and in summer a popular playground for vacationers and fishermen. The island-restricted Drabak Narrows played an important role in Norway’s history during World War II. The Nazi naval forces had planned an invasion of the country by ship under cover of darkness. The commander the Oscarsborg fortress overlooking the narrows fired point-blank on the German battleship Blücher, sinking it and postponing the invasion long enough to allow the royal family and government officials to escape, thus allowing Norway to continue politically as a combatant Allied nation in absentia rather than as a defeated one.