European route E 16 is the designation of a main west-east road through Northern Ireland, Scotland, Norway and Sweden, from Derry to Gävle, via Belfast, Glasgow, Edinburgh, previously by ferry to Bergen, Voss, through the Gudvanga Tunnel and the Lærdal Tunnel (the world's longest road tunnel), Lærdal, over Filefjell to Fagernes, Hønefoss, Gardermoen and Kongsvinger.