Eysturoyartunnilin (Eysturoy Tunnel)

The Eysturoyartunnilin (Eysturoy Tunnel) connects Streymoy and Eysturoy, the two largest of the Faroe Islands, a North Atlantic archipelago located more than 300 kilometers (200 miles) northwest of Scotland. The tunnel, which officially opened to car traffic at the end of 2020, measures over 11 kilometers (6.8 miles) long. At its deepest point, the tunnel is 189 meters (613.5 feet) below sea level. The most interesting part of this infrastructure project, though, is the colorful intersection at its center—the first undersea roundabout in the world.

The roundabout links the capital city of Tórshavn to both sides of the Skálafjørður fjord. Not only is it extra-convenient (cutting down travel time between Tórshavn and Runavík from over an hour to around 16 minutes), it's also a feast for the senses. At its center stands a sculpture created by local Faroese artist Tróndur Patursson. Color-changing lights on a central support structure illuminate a piece of steel that Patursson shaped to represent people participating in a traditional Faroese chain dance. There's even music, composed especially for this unique driving experience—just tune your radio to 97.0 when you drive through the tunnel.

Eysturoyartunnilin is the third underwater tunnel to be built in the Faroe Islands. The first was Vágatunnilin (Vágar Tunnel), which connects the islands of Vágar and Streymoy and opened in 2002. After that was Norðoyartunnilin (the Northern Isles Tunnel), which links Eysturoy and the island of Borðoy and opened in 2006. Another tunnel, the Sandoyartunnilin, is currently under construction. Once complete, it will connect the islands of Streymoy and Sandoy.