Korso is a district and major region in Helsinki metropolitan area, in northeastern Vantaa, Finland. The district has 7,402 inhabitants. Since 2007, the Korso major region has included the following nine districts: Matari, Korso, Mikkola, Metsola, Leppäkorpi, Jokivarsi, Nikinmäki, Vierumäki and Vallinoja. The Korso major region has a total 29,765 i…Korso is a district and major region in Helsinki metropolitan area, in northeastern Vantaa, Finland. The district has 7,402 inhabitants. Since 2007, the Korso major region has included the following nine districts: Matari, Korso, Mikkola, Metsola, Leppäkorpi, Jokivarsi, Nikinmäki, Vierumäki and Vallinoja. The Korso major region has a total 29,765 inhabitants.