The E16 between Gudvangen and Undredal in Vestland runs 11.4 kilometres through the mountain beside the Aurlandsfjord. The tunnel opened in 1991.

It replaced the ferry across the Nærøyfjord, which to this day is part of the UNESCO World Heritage West Norwegian Fjords landscape. In other words, the tunnel is the reason you can drive the E16 ferry-free between Oslo and Bergen here.

This is a typical Sogn mountain tunnel: long, with steep gradients, and exposed to winter chaos. When it closes the detour is long, so check the status before setting out.