Norðoyatunnilin
The 174th longest tunnel in the world
Norðoyatunnilin (The Northern Isles Tunnel) is a two-lane road tunnel under the Leirvíksfjørður in the Faroe Islands. It connects the islands of Eysturoy and Borðoy. The tunnel is 6.2 km long and goes down to a depth of 150 metres below sea level. The maximum gradient is approximately 6%. The tunnel entrances are near the towns of Leirvík on Eysturoy, and Klaksvík on Borðoy. Until the Eysturoyartunnilin opened in December 2020, Norðoyatunnilin was the longest tunnel in the Faroe Islands.
Tunnel data from Wikidata (CC0). Summary from Wikipedia (CC BY-SA).