One great way to show Mother Nature who's boss is to blast a hole through one of the planet's great mountain ranges. And that's exactly what Switzerland hoped to do in 1992 when voters approved funds to build the 35-mile (57-kilometer) Gotthard Base Tunnel through the heart of Europe's Alps. Upon its completion in 2016, it became the longest rail tunnel in the world.
Nothing about the project was easy, fast or cheap. To build the two parallel, single-track tunnels, 2,600 workers had to dig and blast their way through 73 different types of rock and remove 30.9 million tons (28 million metric tons) of debris. An additional 5.2 million cubic yards (4 million cubic meters) of concrete was then pumped back into the tunnel to finish it out. Not surprisingly, the massive project took a whopping 17 years to complete, a figure perhaps overshadowed only by its cost: $12.5 billion. Fully operational, the tunnel is expected handle 260 freight trains and 65 passenger trains a day, each making the trip through the tubes in as little as 17 minutes. That'll take a million trucks a year off the route and help keep the Alps beautiful and peaceful for generations to come [source: BBC].