The Bjørvika Tunnel (Norwegian: Bjørvikatunnelen) is a motorway immersed tunnel on European Route E18 in the city center of Oslo, Norway. The tunnel has two bores, with three lanes in each. In the west, it connects to the Festning Tunnel at Akershus Fortress and runs under the Bjørvika arm of the Oslofjord before ending in an intersection on the east shore, where it splits into Mosseveien (E18) and the . The tunnel is 1,100 metres (3,600 ft) long, 675 meters of which run below sea level, and opened in September 2010. It was built by the Norwegian Public Roads Administration The Bjørvika Tunnel is part of the complex which is the name of the interconnected system of tunnels between Ryen and Filipstad The Bjørvika Tunnel is the first immersed tunnel in Norway.