Under water tunnel

Few days back, I could go under sea water in Oslo area. It was not a swimming but a drive through Oslo FJordtunnelen, in Drammen. The tunnel was 7.2KM long and first went down with a 7% slope till it reached the bottom of the bed rock. Then it again climb up with the same slope. The road tax for the pass cost NOK 55. Last picture is of a nice car.