Welcome to the longest and deepest train tunnel in the world. The Gotthard Base Tunnel finally opened this week in Switzerland, where it travels underground for 35 miles and takes passengers 1.4 miles beneath the surface. It’s part of a series of projects aimed at improving trade routes and reducing pollution from trucks traveling through Europe.
Voters approved the project in 1992. It took $12.5 billion and 17 years of intensive construction to finish, but the Swiss completed it on time.