Drøbak is a town and the centre of the municipality of Frogn, in Viken county, Norway. The city is located along the Oslofjord, and has 13,409 inhabitants. Drøbak and Frogn was established as a parish on its own through a royal decree on 8 September 1823. It had been a part of Ås parish. Drøbak was established as a municipality on 1 January 1838 (see formannskapsdistrikt). It was merged with Frogn on 1 January 1962. Traditionally, Drøbak was the winter harbour of Norway's capital, Oslo, since in severe winters the fjord will freeze from outside Drøbak all the way up to Oslo. It had city status between 1842 and 1962, upon which point the municipality was merged into the rural municipality Frogn and lost its city status. The city status was regained by the municipality council on 13 February 2006. It was also decided that adjacent villages such as Heer would be included within the city. A notable event in Drøbak's history is the World War II sinking of the German cruiser Blücher in the Drøbak narrows (only 1 mile (1.5 km) wide), on the early morning of 9 April 1940. The cruiser was transporting German soldiers and bureaucrats for the planned swift occupation of Oslo, but the Battle of Drøbak Sound, resulting in the sinking by the Oscarsborg fortress delayed this, and thus allowed for the evacuation of the Norwegian royal family, parliament, and cabinet, and for the nation's gold reserves to be denied the occupiers. From early on Drøbak had ferries that crossed the fjord, in modern times it has largely been replaced by the Oslofjordtunnel. However, some of the old ferries are still used as "floating restaurants" during the summer. On the afternoon of 23 July 2023, a car rammed into a crowd of people at a café in the center of Drøbak. According to the local police, more than six people were injured, some of them seriously. The scene of the accident was being investigated by police forensic experts. In summertime, cruise ships visit Oslo almost every day.