Romsås was a borough of the city of Oslo, Norway, until January 1, 2004, when it became part of the Grorud (Romsås) district. By 1850 Romsås was one of the biggest farms in Østre Aker and the name Romsås came from the farm. With the expansion of Oslo city after the second World War, Oslo Kommune allowed OBOS to build a new borough in 1967 and this project was started in 1969. The new borough was divided into 6 neighborhoods ( Tiurleiken, Ravnkollen, Røverkollen, Orremyr, Emanuelfjell and the largest: Svarttjern (often referred to as Øvre og Nedre Svarttjern; upper and lower Svarttjern). Later Romsåslia (more commonly called Romsli) was added as a neighborhood for elderly people. In 1974 the subway station was opened and one year later the mall was opened. Romsås with a population of 7000 people, was the smallest borough of the city of Oslo before it joined Grorud district in 2004. Romsås has one of the highest immigrant populations in Norway and has immigrants from 133 different nations and most of the immigrants come from Asia, The Middle East, East Africa and The Balkan when only counting these people Romsås have about a population of 34-35% immigrants. Romsås has also many immigrants from West Africa and South America (mainly Chile and The Dominican Republic).