Hitra Tunnel

The Hitra Tunnel (Hitratunnelen) is an undersea tunnel in Hitra Municipality in Trøndelag county, Norway. The tunnel connects the island of Hitra to the mainland. The tunnel is 5645 m long and reaches a depth of 264 m below sea level, making it the deepest tunnel in the world when it was built.

The tunnel begins on the island of Jøsnøya, just south of the village of Sandstad. The tunnel then runs under the Trondheimsleia to the island of Hemnskjela. There is a small bridge connecting Hemnskjela to the mainland. The tunnel was built as part of a large project called "Fastlandsforbindelsen Hitra–Frøya". The project also included the construction of the Frøya Tunnel and the construction of a road and bridge network connecting the islands of Fjellværøy and Frøya.

The tunnel has three lanes. Nearly 2,500 cars pass through it every day. Electronics and pumps handle over 38000 L of water per hour.