Grorud is a district of the city of Oslo, Norway. The district contains the Ammerud, Grorud, Kalbakken, Rødtvet, Nordtvet and Romsås areas. To the north of the district is the forest of Lillomarka. The district is the smallest in Oslo, with less than 30 000 inhabitants. The railway station at Grorud is one of the oldest in Norway, and opened in 1854, and was a hub of the whole Grorud valley for many years until the arrival of urbanization and the subway. Some of the old farms are still present in the Grorud landscape, although apartment buildings now are a more dominant part of the scenery.