The Norðoyatunnilin, opened in 2006, is a 6,290-metre subsea road tunnel that runs from Klaksvík under the Leirvíksfjørður to Leirvík on Eysturoy. Before the tunnel, the northern islands were reached from the rest of the Faroes only by car ferry from Leirvík — a journey that ran maybe six times a day in good weather and was often cancelled in winter storms. The tunnel made Klaksvík a 45-minute drive from Tórshavn, transformed the local economy, and is the reason Klaksvík has not depopulated like so many small Faroese settlements.
It is tolled (about 100 DKK each way) and well-lit, and like the more famous newer Eysturoyartunnilin south of it, has a clear engineering appeal of its own — a deep, slowly descending and rising spiral, dropping to 150 metres below sea level at the lowest point. Driving it is the only meaningful way to reach Borðoy unless you fly into Vágar and rent a car.