The Oslo Tunnel (Norwegian: Oslotunnelen) is a 3,632-meter (11,916 ft), double-track, railway tunnel which runs between Olav Kyrres plass and Oslo Central Station (Oslo S) in Oslo, Norway. The tunnel constitutes the eastern-most section of the Drammen Line and runs below the central business district of Oslo. It features the four-track Nationaltheatret Station, Norway's second-busiest railway station, where the Oslo Tunnels lies directly beneath the Common Tunnel of the Oslo Metro. At Frogner, Elisenberg Station was built, but has never been taken into use.