Although Eastern Norway has a number of rivers, none of these flow into the ocean at Oslo. Instead Oslo has two smaller rivers: Akerselva (draining Maridalsvannet, which flows into the fjord in Bjørvika), and Alna. The waterfalls in Akerselva gave power to some of the first modern industry of Norway in the 1840s. Later in the century, the river became the symbol of the stable and consistent economic and social divide of the city into an East End and a West End; the labourers' neighbourhoods lie on both sides of the river, and the divide in reality follows Uelands street a bit further west. River Alna flows through Groruddalen, Oslo's major suburb and industrial area. The highest point is Kirkeberget, at . Although the city's population is small compared to most European capitals, it occupies an unusually large land area, of which two-thirds are protected areas of forests, hills and lakes. Its boundaries encompass many parks and open areas, giving it an airy and green appearance. 